(Updates with Bush in Nevada; changes dateline from Billings) By Tabassum Zakaria ELKO, Nev., Nov 2 (Reuters) - President George W. Bush launched a final drive on Thursday against a strong Democratic challenge for control of Congress, arguing the United States must stay and win in Iraq despite the war's unpopularity. Bush, starting a 10-state sweep seeking to drum up Republican turnout, confronted the unrelenting violence in Iraq that has weighed on his popularity. "The only way we can fail is if we leave before the job is done, and that's exactly what the Democrats want to do," Bush said at a rally in Montana before stopping in Nevada. Polls before Tuesday's congressional elections show Democrats positioned to win a majority in the House of Representatives for the first time since 1994, and threatening Republican control of the Senate. Reflecting the difficult political landscape for Republicans, Bush's pre-election blitz is to states he won as he ran for re-election in 2004: Montana, Nevada, Missouri, Iowa, Colorado, Nebraska, Kansas, Arkansas, Florida and Texas. "We're focusing his energy on places where he can best turn out the vote for Republican candidates. These are all races that are close. These are all races that are likely going to come down to turnout," a senior administration official traveling with Bush said on condition of anonymity. Bush in Nevada showed support for Republicans Dean Heller in his House race, Sen. John Ensign for re-election and Rep. Jim Gibbons, who is running for governor and appeared with Bush at the rally. "Jim Gibbons has addressed his issues. He's been a great member of Congress, he'll be a great governor. The president is happy to campaign with him," the administration official said. A waitress accused Gibbons of assaulting her, which he has denied. Bush first stopped in Montana on behalf of Republican Sen. Conrad Burns, who is in a tight race for re-election after problems including links to convicted lobbyist Jack Abramoff and verbal gaffes on the campaign trail. A Reuters/Zogby poll on Thursday showed Democrat Jon Tester with a 47 percent to 46 percent lead over Burns, who is closing the gap after lagging by four points in early October. THE RIGHT PLAN While Bush pushed other favorite campaign themes, including tax cuts and putting "good judges" on the federal bench, he focused on convincing voters that he had the right plan for Iraq and Democrats did not have a strategy. "Harsh criticism and second-guessing is not a plan," Bush said. Violence has been unabated in Iraq, where October's 104 U.S. troop deaths was the highest monthly toll in nearly two years. Democrats say their party winning control of one or both chambers of Congress would send a strong message to the president that the American people want to change course in Iraq and begin reducing U.S. troops there by year-end. "Even in an election where President Bush is not on the ballot, he is on the ballot. This is really a referendum," Sen. Carl Levin of Michigan, the senior Democrat on the Senate Armed Services Committee, said. "In little places where you never hear this, people are saying they are going to vote on the national issue of whether we are heading in the right direction, particularly in Iraq," he said. A Democratic-led House or Senate would offer a more challenging stance to Bush on Iraq and other issues in his last two years in office than has the Republican-majority Congress. Despite some expert predictions that Republicans could face a rout on Tuesday, Bush insists his party will keep control. "We will win the Senate and we will win the House," he said. (Additional reporting by Steve Holland, and Susan Cornwell in Washington)
