Former Massachusetts Gov. Mitt Romney has become the first big-time New Englander to announce that he’s running for the 2008 Republican presidential nomination. (Some might dispute that he’s really a New Englander; and he seems to be running for office more from Utah, where he went to college and ran the 2002 Winter Olympics, and Michigan, where his father was governor, than from the Bay State.)

He’s probably wise to get going now as an official candidate because he has some impressive competitors. While Mr. Romney did a competent job as governor, cleaned up the aforementioned Olympics, performed very well as an investor and business executive and is rich (increasingly important in running for federal office), he’s still not nearly as well known as the duo who appear to be his biggest rivals: Arizona Sen. John McCain and former New York Mayor Rudolph Giuliani. And some other heavyweights, such as the impressive Sen. Chuck Hagel, of Nebraska, may also enter the race. Meanwhile such luminaries as Kansas Sen. Sam Brownback and former Arkansas Gov. Mike Huckabee are also running. Let us hope that the media do not do the lazy thing and anoint a favored few as “serious” candidates too early in the process. How about actually letting some citizens vote first?

As for Mr. Romney, his reputation for flipping his positions from fairly liberal (to run for office in Massachusetts) to conservative (to run for the nomination of a conservative party based in the South and West) have undermined his credibility a bit.

Finally, his Mormonism might be a problem to some voters, especially to the Evangelical Christians who make up an important part of the GOP coalition.

Still, an articulate, good-looking and competent manager with many family, political and business links to various parts of the country might look very good to a lot of people.

As for his rivals: John McCain conveys a sense of honesty and frankness, is a war hero, and has been a legislative workhorse (as well as publicity hound). Americans tend to like the senator for his directness, and admire his moral and physical courage.

Still, he has serious problems as a presidential candidate. One, of course, is his support for the American military presence in Iraq, which is now very unpopular. He has backed the “surge” of troops into Baghdad even as most Americans are increasingly skeptical about it. If things look better in a few months, he’ll get a lot of credit for standing on principle. If they don’t, he’ll be in very serious political trouble. After all, many Republicans, as well as most Democrats, have turned against the war, too.

Finally, the senator will be 71 this summer, and has had serious health problems, including his injuries from his time as a prisoner of war in Vietnam and melanoma. Many will ask if he will be up to the rigors of the presidency.

As for Rudy Giuliani: He brings a formidable reputation for having cleaned up New York, a city once thought virtually ungovernable. And he topped that off with his sterling command of the city in the catastrophe of 9/11. He evokes a sense of decisiveness that Americans understandably want in their chief executive. His problem is that he’s running for the Republican nomination, and as Nelson Rockefeller once remarked to a newsman who asked him why he could never get nominated for president even when it seemed inevitable he’d win the general election if he could get nominated: “Ever been to a Republican convention?’

Mr. Giuliani support for abortion rights, gay rights and other socially liberal positions associated with that very un-Republican den of iniquity known as New York, not to mention a stormy divorce, place high hurdles to his nomination.

About all we can say with any confidence at the moment, is that the GOP race will probably be as energetic as the Democratic one, but that with the front-loading of the primary system, the whole show might be pretty much over by this time next year.