WASHINGTON — The close race for majority control of the Senate comes down to whether Republican candidates in Massachusetts and Connecticut can win over President Barack Obama's voters and Democrats from Indiana to Arizona can impress Mitt Romney's GOP backers.
Ticket-splitting is vital to the prospects of Senate candidates in a half-dozen races in states that Obama and Romney are expected to win handily. These candidates are significantly outdistancing their parties' presidential nominees in polls, turning what should be an election-year rout into too-close-to-call contests.
With about three weeks to the Nov. 6 vote, Democrats hold a slight edge in keeping their majority in the Senate. GOP hopes have faded in New Mexico and Hawaii while incumbents in Florida and Ohio withstand an onslaught of outside spending to run ahead of their struggling rivals. In an unlikely scenario, races in Indiana and Arizona, once considered certain GOP wins, are competitive.
"The map has expanded over the election cycle," said Guy Cecil, executive director of the Democratic Senatorial Campaign Committee, who credited the class of recruits. "When the cycle started no one gave Democrats a shot at holding the majority."
Still, the mathematical equations of the election remain unchanged.
Democrats hold a 53-47 advantage in the Senate, counting the two independents, and must defend 23 seats to the GOP's 10. The Republicans need a net of four seats to grab the majority if Obama wins and a net of three if Romney captures the White House and Paul Ryan as vice president breaks a Senate tie.
Republicans are counting the open seat in Nebraska as a pickup and are bullish about holding Nevada despite a concerted Democratic effort. They're also upbeat about snatching Democratic seats in close contests in Virginia, Montana and North Dakota. Romney's first debate performance energized the party for the home stretch.
"There's renewed enthusiasm on our side," said Rob Jesmer, executive director of the National Republican Senatorial Committee. In the lineup of ticket-splitting races to watch, one of the biggest surprises and promising opportunities for the GOP in the closing weeks of the campaign is Connecticut.
Former professional wrestling executive Linda McMahon, in her second Senate bid, is running even with three-term Democrat Rep. Chris Murphy in the Democratic-leaning state.
The wealthy McMahon is financing her ads, forcing the DSCC to spend $2 million and counting in a state that's solidly in the Obama column. Although Obama won Indiana in 2008, it's unlikely this year as Romney seems a probable winner along with Republican Rep. Mike Pence in his gubernatorial bid.
Yet Democratic Rep. Joe Donnelly is in a close race with Republican Richard Mourdock, a tea party favorite who unseated six-term Sen. Richard Lugar in the May primary.