WASHINGTON — Just two years after watching Democrats claim a 60th seat in the Senate, Republicans are heading into the 2012 election season well positioned to challenge them for control of the chamber, giving the party reason for optimism even as it worries about the strength of its presidential field.
With Democrats defending 23 seats to their 10, top Republicans believe they have a built-in advantage in their drive to pick up at least the four seats that would vault them into the majority even if President Barack Obama wins a second term and Vice President Joe Biden remains able to break Senate ties. And they calculate that their chances are enhanced because important races will be in relatively conservative states like Montana, Nebraska and North Dakota.
"With our encouragement, I do think people are focusing on the Senate and how that can be the place where we can pick up the most yardage in 2012," said Sen. John Cornyn of Texas, chairman of the National Republican Senatorial Committee.
Democrats are hardly conceding the Senate, and even though the election is 18 months off, campaigns are quickly moving into high gear and contenders are scurrying to raise the millions of dollars they will need.
In Montana, Sen. Jon Tester, the Democratic incumbent, is already engaged in a full-blown fight with his Republican opponent, Rep. Denny Rehberg. An advocacy group is advertising in Massachusetts against Sen. Scott P. Brown, a Republican and a top target of Democrats. Potentially vulnerable incumbents are busily crisscrossing their states.
"I am going like there is no tomorrow," said Sen. Bill Nelson, D-Fla., who faces a tough race in a major battleground state.
The announcement Friday by Sen. Herb Kohl, the four-term Wisconsin Democrat, that he would not seek re-election only added to the difficulties facing Democrats, depriving them of a relatively popular incumbent who could have financed his own campaign. Kohl's exit instead left Democrats with another open seat to protect — their sixth — and added Wisconsin to the list of more than a dozen high-wattage races that will decide control of the Senate, which is now split 53 to 47.
Republicans are even trying to turn concerns about their uncertain prospects in the presidential race into an opportunity in the battle for Senate supremacy, arguing that a Senate takeover could fundamentally alter the balance of power in Washington even if Obama won a second term. They are making the case to donors and voters that winning a Senate majority would give the party control of Congress and a united front against the president from Capitol Hill if Republicans hold the House.
It is not lost on Republicans that the last time a Democratic president won a second term, when Bill Clinton was re-elected in 1996, Senate Republicans still expanded their numbers.
"I am hoping he is not re-elected," Sen. Mitch McConnell of Kentucky, the top Senate Republican, said about Obama. "But it is notable to look back at 1996, when we gained two seats even when we did not succeed. We are focused like a laser on trying to get over the top in the Senate, and we have a reasonable shot."
Reince Priebus, chairman of the Republican National Committee, said that the fight for control of the Senate was among the highest priorities for the party, and that while activists were eager to reclaim the White House, the Senate provided an easier path to changing the direction of Washington.
"The fact that Democrats are running for the hills is making it easier for us to win back the Senate and take full control of the legislative agenda," Priebus said in an interview.
Democrats say the struggle for the Senate is more than a numbers game. Acknowledging that the landscape looked grim in the days after the midterm elections, they say the outlook has improved, partly because House Republicans have pursued a conservative agenda that has allowed voters a good look at the policies Republicans would enact if they controlled both chambers on Capitol Hill.
"It is changing, and it is changing for the better," said Sen. Patty Murray of Washington, chairwoman of the Democratic Senatorial Campaign Committee. "The senators running on our side aren't sitting back. They are raising money, they are being aggressive, they believe in what they are fighting for and they know their states."
Eyeing Republican-held seats in Indiana, Massachusetts, Nevada and elsewhere, Democrats also say they intend to make Senate gains of their own, making it more difficult for Republicans to execute their takeover plans.
Democrats are also counting on an assertive and sophisticated turnout operation by the Obama campaign to substantially reshape the electorate from the one that favored Republicans in 2010.
Both sides essentially put North Dakota in the Republican camp with Sen. Kent Conrad, a Democrat, not seeking re-election, but their views of the Senate landscape diverge sharply from there.
Republicans say they see strong chances of victory in Montana over Tester and in Nebraska, where Sen. Ben Nelson, a Democrat and a former governor, has trailed potential Republican rivals in polls.
"That leaves us 20 more seats to pick up one to get into the majority," Cornyn said.
But Democrats say Republicans are seriously underestimating Nelson and Tester and are overlooking the prospect that Democrats could win Republican seats.Comment on this story
Democrats say that if Sen. Richard G. Lugar of Indiana loses to a conservative challenger in the Republican primary, their candidate, Rep. Joe Donnelly, would have a strong chance running as a moderate. A similar situation could play out in Maine, they say, where Sen. Olympia J. Snowe, a moderate Republican, faces a potential Tea Party challenge. They also have high hopes in heavily Democratic Massachusetts against Brown.
"If you look race by race in each state, I think we are in much better shape than you would have ever imagined," said Sen. Charles E. Schumer of New York, the No. 3 Senate Democrat, who oversaw the campaign operation in 2006 and 2008.
Schumer and others expect Republicans to get tangled up in the sort of messy primaries that cost them in the 2010 Senate races. And they say Republicans have so far failed to recruit top candidates in states that would seem to offer opportunities, like Michigan, Ohio and Pennsylvania.
"They are struggling," said Sen. Sherrod Brown, an Ohio Democrat who is up for re-election next year. "That speaks volumes. If you would have asked right after the election, November or December, I think you would have seen people lining up for those races."