Republican Gov. Scott Walker's recall victory in Wisconsin sets the stage for what's now expected to be a hard-fought presidential battle for this Midwestern state.

The Republican's solid victory served as a warning for President Barack Obama about the potential hurdles he faces as he fights to hang onto a traditionally Democratic battleground he won comfortably in 2008. And, at least for now, it gave presumptive Republican challenger Mitt Romney a reason to feel optimistic about his chances of winning a state that has voted for the Democratic nominee in the past six elections.

The Wisconsin election tested voter attitudes toward Walker's aggressive governing style as well as a law that ended collective bargaining for most public employees and teachers.

"Gov. Romney has an opportunity ... to come in between now and Nov. 6 and make the case that he's willing to make those same sort of tough decisions," Walker told Fox News Channel on the eve of his victory.

In the coming days, national Republicans and Democrats alike will re-evaluate the Wisconsin political landscape. In setting their presidential campaign strategies, they will take into consideration the state's 6.7 percent unemployment rate - lower than the national average - the heavy chunk of independent-minded voters and the partisan atmosphere that led to the effort to recall Walker.

Both Obama and Romney had been waiting until after the recall election to determine how hard to compete here. Even so, their teams had been hinting in the days leading up to the recall about how Wisconsin's 10 electoral votes fit into their state-by-state game plans for reaching the 270 electoral votes needed for victory.

Obama's team, which has been on the ground organizing but hasn't spent money on advertising for months, signaled this week that it believed the state had grown more competitive. In May, campaign manager Jim Messina had said Wisconsin was trending toward the president. By Monday, he was listing Wisconsin as "undecided."

There's no doubt now that Obama will defend his turf. Not that he has much of a choice.

Romney now plans to compete in the state aggressively, looking to capitalize on the Republican momentum that carried Walker to victory. His team considers Wisconsin a top target, along with Florida, Ohio and Virginia, and more attractive than even Romney's native Michigan, where the campaign had hoped to establish an Upper Midwest beachhead.

"The close vote on Tuesday confirms that Wisconsin will be a swing state," said Republican strategist Terry Nelson, an adviser to George W. Bush.

An exit poll of voters Tuesday that was conducted for The Associated Press sketched the state of the race in Wisconsin five months before the election, though November's electorate might be substantially different.

Walker supporter Susan Piekenbrock said his victory would likely mean she'd support Romney but not guarantee it.

"Do I like everything Romney says? No," said Piekenbrock, a longtime Democrat-turned-independent from West Allis, a western suburb of Milwaukee. "I'll support Romney if the reform theme is the same as Walker's."

Danielle Scriver's support for Walker is synonymous with Romney. "When you consider Obama is the alternative, it's automatic," the Republican from Racine said.

Obama had a 51-44 percent edge over Romney in exit polling, and more Wisconsin voters said that the president would do a better job improving the economy and helping middle-class voters than his GOP rival would. A sizable 1 in 5, however, said they trust neither party's candidate on the economy, the main issue in the presidential campaign.

"These data points clearly demonstrate a very steep pathway for Mitt Romney to recover in the state," Obama's Wisconsin campaign director, Tripp Wellde, said in a statement.

But there are warning signs for Obama, too.

Independent voters, who made up a third of the recall electorate and typically decide close elections, broke for Walker 53-45. And the power was on display of both the GOP's robust national get-out-the-vote effort and of deep-pocketed Republican super political action committees, which poured $18 million into the state to help Walker. Unions, a key Democratic constituency, failed to get their rank-and-file members to rally behind Barrett, an ominous sign for a Democratic presidential candidate counting on those ground troops.

Four years ago, Obama won the state by 14 percentage points. Democrats John Kerry in 2004 and Al Gore in 2000 carried the state by less than a single percentage point. Observers say Tuesday's results may foreshadow a similar scenario in November.

Neither Obama nor Romney had run TV ads in the state though that likely will change, with campaigns and super PACs alike gearing up to pour money into Wisconsin.

Expect both candidates to visit more frequently, too. Obama and Romney had steered clear of the state in the heat of the recall campaign.

Obama, careful not to weigh too deeply into what ended up being a losing race, didn't campaign for Democratic Milwaukee Mayor Tom Barrett. Instead, the president posted an endorsement of Barrett on Twitter and emailed a Web video to Wisconsin supporters encouraging them to back Barrett. Obama also dispatched top surrogates including former President Bill Clinton and Democratic National Chairwoman Debbie Wasserman Schultz to the state.

Romney, for his part, has not visited Wisconsin, advertised here or had staff on the ground since winning the Republican presidential primary in April. Campaign officials said the former Massachusetts governor plans to convert the 26 offices that helped Walker into get-out-the-vote centers for his candidacy.

Romney hailed Walker's triumph as an endorsement of conservative fiscal policy, not a plug for the status quo, with national implications.

The results, he said in a statement, "will echo beyond the borders of Wisconsin."

While Obama has included Wisconsin in most of his scenarios for winning the White House, he conceivably could win a second term without it. But having to compete aggressively for Wisconsin means Obama will have fewer resources to spend in high-priority targets like Ohio and Florida.
"As both campaigns look at the data in the coming days and weeks, I think it's going to show that Wisconsin is a state that's a toss-up in the presidential campaign," said Romney's political director, Rich Beeson.
Democratic pollster Paul Maslin is betting that Walker's win will motivate Obama supporters from 2008.

"People aren't going to abandon their judgment," said Maslin, who is based in Madison and polled for Barrett's primary opponent Kathleen Falk. "That's why I think, at the end of the day, if it's really close, Obama wins."