McCain turns to November: Can he win?

WASHINGTON (Reuters) - Now that he is the U.S. Republican presidential nominee, John McCain faces a huge challenge: How to beat recent history and win a third straight White House term for his party.

McCain scored victories in Texas, Ohio, Vermont and Rhode Island on Tuesday to complete his improbable comeback from the political graveyard last summer to become his party's standard-bearer.

The Arizona senator quickly pivoted to a November presidential election matchup against either Democrat Barack Obama or Hillary Clinton, pledging in a victory speech to make a "respectful, determined and convincing case" to Americans.

"Our campaign must be, and will be more than another tired debate of false promises, empty sound-bites, or useless arguments from the past that address not a single American's concerns for their family's security," he said.

He faces an uphill battle against either Obama or Clinton.

In the last 50 years, only once has the party in power for two terms in a row been able to win a third one, when George H.W. Bush, the current president's father, succeeded the immensely popular Ronald Reagan in the 1988 election.

And this year the call for change is plaintive: The U.S. economy is in trouble, Americans are tired of the Iraq war, and most are ready to move on from unpopular President George W. Bush.

Democrats are already trying to portray McCain as in search of a "third Bush term."

But polls show McCain matching up well against either Democrat.

And political experts say a path to victory does exist for McCain. They point to his ability to reach beyond his party's conservative wing and attract independent and moderate voters.

"The Republicans almost by accident have picked the only candidate in their entire field who might luck into a victory," said Larry Sabato, director of the University of Virginia's Center for Politics.

"It will be very tough. It'll be a narrow victory if there is one, and everything will have to go almost entirely right for McCain to win," he said.

Republicans concede that Democrats have a large advantage in enthusiasm and fund-raising this year with two strong candidates, but they believe McCain now has time to try to close the gap and unite the Republican Party behind him.

He will take a step in that direction on Wednesday when he travels to the White House to be endorsed by Bush. He and Bush have not always seen eye to eye, but McCain has said he will welcome the president's support.

"Bush's role should be fund-raiser-in-chief for the entire Republican ticket from the White House to the courthouse," said Republican strategist Scott Reed. "He doesn't need to be a campaign fixture with McCain. But he needs to help build up the financial coffers."

McCain senior adviser Charlie Black said McCain will have an advantage by the prolonged Democratic battle between Obama and Clinton.

"I think we'll have the luxury of total focus on the general election starting tomorrow," Black said. "It might give us some advantage in making use of our time."

McCain, 71, starts out on the eight-month race to November as the most experienced candidate on national security, having served as chairman of the Senate Armed Services Committee. He is considered a war hero for having spent 5 1/2 years as a Vietnam prisoner of war.

But his support for the Iraq war will be fodder for attacks. McCain said in is victory speech that the next president must explain how to bring about the "swiftest possible conclusion" to the war without making it worse and destabilizing the Middle East.

Reed said McCain can make the case against Obama, for example, simply by trying to raise the same doubts about the first-term Illinois senator that Clinton has done in recent days with a television advertisement questioning who do you want to answer the White House crisis phone at 3 a.m .

"I'm more upbeat and optimistic than I've ever been because the Democrats are destroying each other. And all we need to do if Obama is the nominee is run the Clinton ad and add a disclaimer that says it was paid for the Republican National Committee. It's not really much more complicated than that," Reed said.

(Editing by David Wiessler)

(To read more about the U.S. political campaign, visit Reuters "Tales from the Trail: 2008" online at blogs.reuters.com/trail08/