The next 98 days will be a time of testing for the men and women running for the 2012 Republican presidential nomination.

With the field largely settled, the three months between Memorial Day and Labor Day amount to the first extended period in which the candidates must learn how to interact with one another and, more important, with voters. This is when the race truly begins.

There will be at least three debates during this time: one in New Hampshire, one in Nevada and one in Iowa. The contenders will report their fundraising totals for the preceding three months in mid-July, a make-or-break moment for some. And then comes the Ames straw poll on Aug. 13 in Iowa, the first real test of grass-roots energy and organizational heft for the wannabe nominees.

With all of that activity on the horizon, it’s worth looking at where the race stands now and where it’s likely to head in the next 98 days.

Former Massachusetts governor Mitt Romney, who plans to announce his bid on Thursday in New Hampshire, is the front-runner — a position strengthened by the recent decisions of former Arkansas governor Mike Huckabee and Indiana Gov. Mitch Daniels not to enter the race.

“Romney has been running an incredibly disciplined campaign, not allowing external forces to determine the strategy or timeline they think is best,” said Christian Ferry, a Republican strategist who served as deputy presidential campaign manager for Sen. John McCain (Ariz.) in 2008.

Romney, who raised more than $10 million in a single day this month, is almost certain to go for a shock-and-awe fundraising filing in July — a showing that will, at least temporarily, strengthen his hand as the leading GOP candidate.

If Romney as the race’s front-runner appears more settled, so, too, does the second tier of candidates aiming to be the alternative to him.

“The big factor I am seeing is Republican voters don’t want to go down the road again of picking the ‘next one in line,’ ” said Ed Goeas, a Republican pollster not aligned with any presidential campaign. That phenomenon, coupled with the Massachusetts health-care legislation Romney signed as governor, has created “a ceiling in the high 20s at best” for the front-runner, he added.

Former Minnesota governor Tim Pawlenty holds the pole position to be the anti-Romney, having benefited over the past few months from hard work and luck. Without Huckabee in the race, he is now well positioned to win Iowa’s caucuses, a victory that would catapult him to instant credibility in the New Hampshire primary and beyond.

Less predictable but potentially more intriguing is former Utah governor Jon Huntsman, who returned from his post as ambassador to China less than a month ago and appears to be all but in the race.

Working for Huntsman are his personal wealth, his relative newness on the national stage and a foreign-policy expertise that’s lacking in the field. Working against him is his time spent working for Obama, as well as his support for civil unions and cap-and-trade energy legislation — positions that have created the idea that he is the moderate in the race.

For Huntsman, more than any other candidate in the field, the next 98 days will be essential in determining whether he is a contender or a pretender for the nomination as he seeks to turn buzz and solid staff hires into committed voters in early states.

“Electability is going to matter,” GOP consultant Alex Castellanos said. “That means, unless the field changes, only one of these three can win the nomination.”

The rest of the field is largely jumbled at the moment, although Rep. Michele Bachmann (Minn.), who is expected to announce her candidacy next month, is deserving of a special mention because many regard her as a potential winner of the Iowa caucuses. Most GOP observers think Bachmann lacks the capacity or message strength to build a win in Iowa into a broader push for the nomination, however.

The other question is whether former House speaker Newt Gingrich (Ga.) can recover from a disastrous start to become a legitimate factor in the race.

And then there are the candidates-in-waiting (or not). With polling suggesting that large numbers of Republican voters are unhappy with the current lineup, there is constant chatter about a late entrant swooping in and changing the calculus.

“There will be a flavor of the week from now until fall,” GOP strategist Matt McDonald said.

At the top of that list is former Alaska governor Sarah Palin, who began a bus tour Sunday that is stoking speculation about her renewed interest. She has set not timetable for a 2012 decision, however, and even those close to her know little about her plans.

Texas Gov. Rick Perry has opened the door on a bid, but his closest allies still cast doubt on the idea. New Jersey Gov. Chris Christie has remained adamant that he won’t run.

Ninety-eight days from now, Palin, Perry and the rest of the fence-sitters will either be in or out. Romney is likely to still be the front-runner on Labor Day, with Pawlenty’s status as the establishment alternative dependent on his fundraising and his showing in the Ames straw poll. Huntsman will have proved himself to be a boom or a bust by then. Gingrich will have bounced back — or not. Bachmann will be an Iowa front-runner or an also-ran.

Stay tuned. It’s going to be a doozy.