Denver ? Overshadowed by his rival’s convention, Republican John McCain is hours away from grabbing back the spotlight by choosing his running mate.

McCain is expected to announce his choice Friday in Ohio, just as the newly nominated Democratic team of Barack Obama and Sen. Joseph Biden, D-Del., roll out of their convention in Denver and McCain heads to Minnesota for his nominating convention next week.

McCain hasn’t given any clue, but Republican insiders and analysts say that a fast-changing landscape in recent days has helped some potential choices and hurt others.

Among the changes:

¢ McCain has pulled into a neck-and-neck fight with Obama after trailing for weeks. He led 46-44 percent in a Gallup daily tracking poll released Tuesday. That lessens the need for him to make a dramatic long-shot pick such as Carly Fiorina, the former Hewlett-Packard chief executive officer, to shake up the race.

¢ He’s shored up support from social conservatives and has seen a payoff in the polls. That could make him less inclined to anger them now with an abortion-rights supporter such as former Pennsylvania Gov. Tom Ridge.

¢ Obama picked Biden, an experienced hand in foreign policy and debates, which could put a new emphasis on finding someone who could take on Biden in the vice presidential debate this fall.

The pick is crucial for McCain, especially as he announces it Friday on his 72nd birthday, which calls attention anew to his age and to speculation that he might serve only one term if elected.

“The Republican Party is the-next-guy-in-line party. Whoever he picks as vice president could become the next guy in line. If he picks a mainstream conservative, then the conservatives can get excited not just about the McCain candidacy but the future of the party,” said Greg Mueller, a Republican strategist.

Here’s a look at the most-mentioned contenders in three categories.

The mainstream

Minnesota Gov. Tim Pawlenty and Massachusetts Gov. Mitt Romney top most lists.

“A week ago, Romney and Pawlenty looked like the two most likely conservative choices. But I think over the last several days, events have conspired against both of them,” said Dan Schnur, a former aide to McCain in the 2000 campaign who’s now the director of the Jesse M. Unruh Institute of Politics at the University of Southern California.

Schnur said Pawlenty might not match up well with Biden in a debate and that the flap over McCain not remembering how many homes he and his wealthy wife owned made it more difficult to pick another wealthy candidate such as Romney.

The big tent

McCain has said kind things about two potential running mates who support abortion rights, Sen. Joseph Lieberman, an independent Democrat from Connecticut, and Ridge.

Such a choice would boost McCain’s image as a maverick who is willing to buck his party base. McCain has long had a strained relationship with social conservatives, but he won kudos during a recent forum on faith in California.

Lieberman remains a wild card, however, because McCain likes him.

The long ball

Two things might lead McCain to make a very unconventional pick such as Fiorina or eBay CEO Meg Whitman: the idea that he’s trailing and needs to shake things up with someone from outside government, or that picking an accomplished woman would help him attract the votes of women who supported Hillary Clinton and are angry that Obama passed her over for his running mate.