WASHINGTON — The 2006 campaign, one of the nastiest battles and the most expensive ever for control of Congress, came to an end Monday amid indications that months of debate over Iraq, political corruption and the Republican dominance of Washington could produce the highest voter turnout in decades for a midterm election. Even as polls differed on whether voters were ready to hand Democrats a majority in the House or Senate, or both, a series of late surveys consistently showed extremely high levels of interest in the election.
In a national USA Today/Gallup Poll released Monday, 68% of adults said they were "absolutely certain" they would vote. That was the highest level of interest Gallup has recorded for a nonpresidential election in the half a century it has measured American opinion.
Likewise, a survey by the Pew Research Center for the People & the Press showed a significantly higher level of interest than in the last two midterm elections -- higher even than in 1994, when Republicans swept Democrats from power in Congress.
Iraq, the issue that has generated the sharpest conflicts between President Bush and the Democrats, continued to set off sparks on the campaign's final day.
Leading Democrats urged Americans to demand a new direction on Iraq policy by ousting the GOP majorities in the House and Senate.
"The choice couldn't be more stark," Sen. Charles E. Schumer (D-N.Y.), chairman of the Democratic Senatorial Campaign Committee, told reporters. "Every vote cast for a Democrat is [a vote] for a new, smarter Iraq policy. Every vote cast for a Republican is a vote cast for staying the course."
Bush, accepting that gauntlet, portrayed success in Iraq as essential to protecting America's national security and insisted that Democrats had no plan to prevail there.
"Harsh criticism is not a plan for victory," Bush told an enthusiastic crowd of 5,000 in the Republican stronghold of Pensacola, Fla. "Second-guessing is not a strategy. We have a plan for victory, and part of that plan is to make sure that Republicans control the House and the Senate."
With all 435 seats in the House of Representatives and 33 Senate seats at stake, as well as 36 governorships, today's election could mark the sharpest turn in American politics since the Republican landslide in 1994.
GOP dominance at risk
Since that victory, fueled by a backlash against President Clinton's first two years in office, Republicans have controlled the House for 12 consecutive years and the Senate for all but about 18 months in Bush's first term.
Now polls show that voter discontent over Bush's direction, especially in Iraq, has carried the Democrats within range of capturing at least one chamber of Congress. Republicans took heart from several late surveys showing the GOP mobilizing more of its core supporters and shrinking its deficit among swing voters, much as the party did in the final weekend before its surprising gains in the 2002 election.
"Our party is heading into election day with strong momentum," Republican National Committee Chairman Ken Mehlman said in an e-mail to supporters Monday morning.
Still other polls painted a less-promising picture for the GOP. And most analysts on both sides agreed it would be extremely difficult for Republicans to prevent Democrats from securing the 15-seat gain they need to capture a majority in the House.
In the Senate, Democrats face a tougher climb. They need a gain of six seats to reach a majority, and that will require them to capture at least four of the five most closely contested Republican-held seats -- in Rhode Island, Montana, Virginia, Tennessee and Missouri -- without losing any seats they already hold.
Public opinion polls generally showed close races in all of those contests except Tennessee, where most surveys provided Republican Bob Corker a wider advantage over Democratic Rep. Harold E. Ford Jr. Late polls showed Democratic challengers maintaining large leads over Republican Sens. Rick Santorum in Pennsylvania and Mike DeWine in Ohio.
A Democratic majority in either chamber could set the stage for two years of intense political conflict. Democrats would be likely to use the subpoena power that comes with majority control to aggressively examine Bush policies in Iraq and at home that they argue Republican lawmakers have failed to monitor.
Big Democratic gains would also disrupt the ambitions of Bush and Karl Rove, his chief political advisor, to build a lasting Republican electoral majority centered on an alliance of economic and social conservatives.
One of the hallmarks of Bush's presidency has been the passionate emotions he inspires in supporters and opponents, and that pattern shows every sign of generating a large turnout today.