Chafee, who has clashed frequently and vociferously with the administration over tax cuts, the war in Iraq, and the president's pick of Samuel Alito for the Supreme Court, found himself a welcome beneficiary of the party's financial largess and powerful get-out-the-vote effort in the final 72 hours. With control of the Senate possibly hanging in the balance, the national party apparatus picked Chafee, going with name recognition, incumbency, and moderation in the closely watched primary race.

That bet panned out. Chafee defeated Laffey, an investment banker and mayor of Cranston, R.I., by eight percentage points, 54 percent to 46 percent, in an election that saw historic voter turnout at 63,000, with surging interest among independents who can vote in the Republican primaries.

"Senator Chafee's independent, honest leadership drove a historic turnout and clearly shows he is in a great position to win in November," said Sen. Elizabeth Dole, chair of the National Republican Senatorial Committee, which along with the Republican National Committee backed Chafee with roughly $1 million.

Laffey, meanwhile, had received support from the conservative Club for Growth, a Washington-based group advocating small government and low taxes that has stridently opposed Republican moderates like Chafee, even if that means compromising the party's chances to hold on to seats in the fall.

"The NRSC and the RNC deserve a lot of credit here for helping Chafee pull across the line," says Jennifer Duffy, of the Cook Political Report.

For Democrats, Chafee's win makes winning control of the Senate one seat harder. Polls have shown Democratic nominee Sheldon Whitehouse soundly besting Laffey but in a dead heat against Chafee.

"The general election will be very competitive," says Darrell West, a Brown University professor who studies Rhode Island politics. "This will remain a close race until the end." And the race also perhaps augurs that despite low public approval ratings for Congress as a whole and strong anti-incumbent sentiments on display last month in Sen. Joe Lieberman's primary loss in Connecticut, voters still may not be so quick to drop their own representatives and senators. -- Silla Brush