HOBBS, NM -- Mitt Romney returned to oil country this morning to sell his new energy plan, setting a goal of reaching North American energy independence by 2020 in large part by removing regulatory barriers to fossil fuel development in the United States, and increasing cooperation with fellow energy-producers Canada and Mexico.

"I will set a national goal of America and North America -- North American energy independence by 2020," Romney pledged. "That means we produce all the energy we use in North America. And there are a number of things I'm going to do to make that happen. It is achievable. This is not some pie in the sky kind of thing. This is a real, achievable objective."

Evan Vucci / AP

Republican presidential candidate Mitt Romney speaks during a campaign event at Watson Truck and Supply Aug. 23.

Romney's plan, laid out in a white paper and conference call with reporters last night, calls for streamlining the permit process for energy development on federal lands and offshore, for building infrastructure like the Keystone Pipeline, and supporting basic research on next-generation fuels like wind and solar, while abandoning subsidies and loan guarantees that, Romney argues, have tilted the marketplace in favor of those energy sources.

With the plan largely fleshed out before Romney's remarks, the candidate took on the role of chief salesman for his plan today, telling a crowd of a few hundred supporters here there would be ancillary benefits to boosting domestic energy production beyond lowering energy prices at home.

"Three million jobs come back to this country by taking advantage of something we have right underneath our feet, that’s oil and gas and coal, we’re going to make it happen we’re going to create those jobs," Romney said.

"Let me tell you what else it does," Romney continued "It adds $500 billion to the size of our economy. That’s more good wages, that’s an opportunity for more Americans to have a bright and prosperous future. It also means by the way tens of billions, potentially hundreds of billions of dollars of tax revenues going into states and the federal government, which can make sure we have a military second to none and schools that lead the world and care for our seniors, better roads and bridges."

Romney also argued that becoming less dependent on unstable or hostile regimes for energy increases America's national security.

"This is not just a matter of economy and jobs and rising incomes and the growing economy and more tax revenues. It’s also more security. It means we don’t have to rely on people who in some cases don’t like us very much," Romney said.

Democrats responded to Romney's remarks with a statement.

"He will embrace a backward, drilling-focused energy policy that prioritizes subsidies and tax breaks for the big oil and gas companies and leaves behind efforts to increase energy efficiency and develop homegrown alternative energy," Obama campaign spokesperson Lis Smith wrote in a statement to reporters. "This isn’t a recipe for energy independence; it’s just another irresponsible scheme to help line the pockets of big oil while allowing the U.S. to fall behind and cede the clean energy sector to China."

Romney's choice of venue for publicly unveiling his plan raises some questions about his campaign strategy. The presumptive GOP nominee had not previously campaigned or run television ads in New Mexico, and while the state ranks 6th in oil production, according to government assessments, it is not considered a swing state. President Obama carried the state in 2008, and NBC's current battleground map, debuted this morning, places it in squarely in the "Lean Democratic" category.

Updated 12:35 p.m. -- Democrats and Republicans each found something to cheer in the Supreme Court's ruling Monday on Arizona's controversial immigration law, reflecting the delicate politics surrounding immigration and the court's own mixed decision.

Each party found something to like and dislike in the Supreme Court's opinion, which struck down most components of the Arizona law but left in place one of its most controversial provisions: the requirement that authorities check the immigration status of anyone they detain who's reasonably suspected of being in the United States illegally.

President Obama said he was "pleased" the court had struck down key provisions of the law, while his likely Republican opponent, Mitt Romney, suggested the decision represented a rebuke of the president.

"What this decision makes unmistakably clear is that Congress must act on comprehensive immigration reform. A patchwork of state laws is not a solution to our broken immigration system -– it’s part of the problem," Obama said. "At the same time, I remain concerned about the practical impact of the remaining provision of the Arizona law that requires local law enforcement officials to check the immigration status of anyone they even suspect to be here illegally."

Romney, meanwhile, emphasized what he said were the president's own struggles to curb illegal immigration.

"Today's decision underscores the need for a president who will lead on this critical issue and work in a bipartisan fashion to pursue a national immigration strategy," presumptive Republican nominee Mitt Romney said in a written statement.

Yuri Gripas / Reuters

People protest against President Obama's health care reform in front of U.S. Supreme Court in Washington June 25.

But Romney didn't address the components of the law that were thrown out or, alternatively, upheld by the court.

"I believe that each state has the duty -- and the right -- to secure our borders and preserve the rule of law, particularly when the federal government has failed to meet its responsibilities," he said.

Both Obama and Romney's responses were emblematic of the mixed reactions prompted by the decision across the political spectrum.

Senate Majority Leader Harry Reid (D-NV) said the decision marked a vindication of the Obama administration's initial decision to challenge the Arizona law. Critics in the Democratic Party said that the law, including the prong that the Supreme Court upheld, would open the door to racial profiling.

"This is as strong a repudiation of the Arizona law as one could expect given that the law has not been implemented yet," said New York Sen. Charles Schumer (D). "Three linchpins of the Arizona law were struck down by a convincing majority of the Court as clearly violating federal law, and a fourth is on thin legal ice."

But Republicans found just as much to cheer in the court's ruling.

Arizona Gov. Jan Brewer, who first championed the law, called the decision "a victory for the rule of law."

While many elements of the law were struck down, the court upheld what Brewer called the "heart" of the law -- a requirement that authorities check the immigration status of anyone whom they suspect of being in the United States illegally.

The state's two Republican senators, Jon Kyl and John McCain, also cheered the court for appearing to validate the status-check portion of the Arizona law.

The president will participate a series of public events set Monday in New England; as a matter of coincidence, Romney is in Arizona today to attend fundraisers.

The issue of immigration has assumed broader political significance in the 2012 campaign, following the president's announcement earlier this month that his administration would cease deporting illegal immigrants who were brought to the United States as children and would instead allow them to apply for temporary work visas. This shift, which achieved many of the intentions of a Republican version of the DREAM Act, was poised to mobilize Latino voters behind the president, who had otherwise fallen short on delivering on his promise of comprehensive immigration reform.

The administration's announcement also threatened to exacerbate Romney's gap against Obama among Latino voters, a growing bloc that could prove especially decisive in swing states like Arizona, Colorado, Nevada and beyond. An early May oversample of Latino voters in the NBC News/Wall Street Journal poll found that 22 percent of Latinos had a positive opinion of the GOP, versus 50 percent who expressed a negative impression of the Republican Party.

Romney responded to the new immigration policy by promising to supersede it with his own "long-term" plan on immigration. But he hasn't specified how his plan would work, or what it would differ in practical terms from the Obama plan.

The former Massachusetts governor has wrestled with immigration as an issue writ large, but has also struggled with positioning himself on the Arizona law.

Romney called the Arizona law a "model" at a debate this February, though his campaign insisted Romney only meant that in terms of some of the employment parts of the law (which the Supreme Court threw out on Monday). The Romney campaign was also forced to distance itself from Kansas Secretary of State Kris Kobach (R), one of the principal authors of the Arizona law and another tough immigration law in Alabama.

But Romney also said at the same debate that "the right course for America is to drop these lawsuits against Arizona and other states" in addition to more aggressive enforcement of immigration laws.

Romney had used immigration to pummel some of his opponents in the Republican primary from the right, making his pivot toward the general election even more difficult.

California voters turned out in low numbers on Tuesday for a primary that could pave the way for a shakeup of the state's congressional delegation following election rule changes and an overhaul of the state's political district boundaries.

While new maps and new rules may have changed the way the game of California politics is played, making some districts more competitive across party lines, early official estimates of statewide turnout hovered at just over 15 percent.

Under California's new open primary rules, the two top vote getters in each district will proceed to the general election in November regardless of party, so two Democrats or two Republicans could be competing for the same seat come Nov. 6.

Redistricting has also tossed some longtime incumbents into the ring against each other after a decade of remarkable stability in the state's majority Democratic delegation in the House of Representatives.

In one of the most closely watched races, where two Democratic incumbents appeared poised to face off against one another in the general election, just a trickle of voters cast ballots on a sunny day in California's 30th district in Los Angeles County, according to early results.

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Among those casting ballots there were 82-year-old Ester Berrenson and her husband of 64 years, 86-year-old Manny, who walked to their polling station during the breezy afternoon. Both voted for Democratic incumbent Brad Sherman against fellow Democratic incumbent Howard Berman.

"He comes out and talks to us," Manny Berrenson said, explaining why he and his wife had voted for Sherman. "He goes to the high school at least half a dozen times a year. He goes there and talks about what he's doing."

Due to the "top two" rule, both are likely to advance to a final competition in November, according to early returns. Sherman had 40.3 percent to Berman's 32.6 percent just after midnight with 18 percent of precincts reporting.

In their newly redrawn district, about 50 percent of voters there come from Sherman's old stomping ground, while just 25 percent come from Berman's prior district.

"Tonight is far from over, but we're confident about our momentum moving into the general election," a senior adviser to Berman's campaign, Brandon Hall, said in a statement.

Changes favor Democrats

The changes in California are generally seen to favor Democrats in a state that gave President Barack Obama a 24-point margin of victory over his Republican rival John McCain in 2008, analysts said.

Two incumbent Democratic congresswomen, Janice Hahn and Laura Richardson, also appeared set to face off against each other in November in the 44th district in Los Angeles County in a race in which no Republicans were running.

Shortly after midnight, Hahn was leading with 62.1 percent with 6.5 percent of precincts reporting.

For years, political stability in the nation's most populous state was a result of the deliberate creation of electoral districts to favor incumbents, a process known as gerrymandering. In 263 elections from 2002 to 2010, only one congressional seat changed political party.

But ahead of this election, a non-partisan citizen's commission was put in charge of redrawing congressional districts. The number of districts did not change, but the boundaries were adjusted to reflect population shifts since the last national census in 2000.

"With non-partisan redistricting and this new 'top two' primary system, California suddenly becomes very interesting and one of the more competitive states in the entire country," said Kyle Kondik, political analyst at the Center for Politics at the University of Virginia.

In their quest to win back a majority in the U.S. House of Representatives, Democrats would have to gain at least four or five seats in California, which Kondik said would be difficult but not impossible.

Democrats made progress in one key U.S. House race where analysts had said they risked being frozen out of the general election should a Republican and a right-leaning independent candidate advance to the November polls.

But, as early returns trickled in, Democratic state Assemblywoman Julia Brownley appeared poised to face a Republican challenger, state Senator Tony Strickland, in November in California's coastal 26th district.

Republicans control the House with a 242-190 majority, with three seats vacant. Outside California and Illinois, Democrats are mainly playing defense, trying to hold existing seats.

Nationwide battle

Primaries were also held on Tuesday in New Jersey, New Mexico, Montana, South Dakota, North Dakota and Iowa.

In Montana, the U.S. Senate battle is one of the nation's hottest with the state's only House member, Republican Denny Rehberg, challenging first-term Democratic Senator Jon Tester.

Both candidates are known across the state and are expected to easily win their respective party primaries on Tuesday.

In Iowa, State Representative Pat Grassley - the grandson of U.S. Senator Chuck Grassley - won his primary, defeating another Republican in the Iowa House in a contest forced upon him and State Representative Annette Sweeney by redistricting.

Republicans are targeting the New Mexico U.S. Senate seat of retiring Democratic Senator Jeff Bingaman in their quest for a U.S. Senate majority in 2012. Democrats hold a 51-47 majority, with two independents who usually vote with Democrats.

Republican Heather Wilson and Democrat Martin Heinrich are projected to win their respective party races and run against each other for the coveted Bingaman seat, according to Brian Sanderoff, president of Research and Polling Inc in Albuquerque.

In New Jersey, polls are closed in the vote to fill the seat of U.S. Representative Donald Payne, the state's first black congressman, who died in March. His son is among the candidates.