By Rosalind S. Helderman and Jason Horowitz
The Washington Post
In the battle for control of the U.S. Senate, there are now at least eight critical contests in which polling shows essentially a dead heat, encouraging Republicans' hopes that they may yet snag the chamber, which very recently seemed beyond their reach.
Some of the GOP boost is coming from the top of the ticket in the form of Mitt Romney, whose recent surge in the polls seems to be helping Republican candidates across the country.
Democrats still have an edge in their effort to keep control of the Senate, and they may have been helped Tuesday when Republican candidate Richard Mourdock in Indiana suggested that pregnancies resulting from rape are God's will, possibly damaging his chances to succeed Sen. Richard G. Lugar, the Republican incumbent whom Mourdock defeated in the primary.
But both parties agree that many of the most important races have become more competitive in recent days, and their outcomes harder to predict.
Senate contests in the presidential battlegrounds of Wisconsin and Virginia, where Democrats had leads in polls a few weeks ago, are now essentially even and could be especially influenced if Romney performs well in those states. Polls show Democratic incumbents in Ohio and Florida still ahead, but those races have tightened as Romney has gained ground in the states. And the Senate races in Connecticut and Pennsylvania, long thought to be safe wins for Democrats, have become real contests.
Both parties and independent groups are now investing heavily in a remarkably long list of states stretching from Maine to Hawaii.
To take control of the Senate, Republicans would need a net gain of four seats if President Barack Obama were reelected, but only three if Romney won. In that case, Paul Ryan, as Romney's vice president, would become the Senate's tiebreaking vote.