You can marvel at the risk averseness of a pol who endorses a presidential candidate only after his nomination is effectively sewn up, but former Florida Gov. Jeb Bush’s stamp of approval is a big moment for Mitt Romney. His statement read:

Congratulations to Governor Mitt Romney on his win last night and to all the candidates for a hard fought, thoughtful debate and primary season. Primary elections have been held in thirty-four states, and now is the time for Republicans to unite behind Governor Romney and take our message of fiscal conservatism and job creation to all voters this fall. I am endorsing Mitt Romney for our Party’s nomination. We face huge challenges, and we need a leader who understands the economy, recognizes more government regulation is not the answer, believes in entrepreneurial capitalism and works to ensure that all Americans have the opportunity to succeed.

If the other “white knights” (the guys unwilling to run, but for whom many on the right pined) like Indiana Gov. Mitch Daniels, Louisiana Gov. Bobby Jindal, Rep. Paul Ryan (R-Wis.), and Sen. Marco Rubio (R-Fla.) come forward, I suspect the nail will be firmly embedded in the coffin.

On one level, you can say it’s silly that Jeb Bush's statement means anything. The delegate count is the delegate count, as we have said many times. But this is a move to demoralize and dissuade Romney rivals from persisting. Bush's message, which is sure to be echoed by others, is that if you don’t get on board you are hurting the party’s chances against Barack Obama. Casting opponents as nothing more than bad sports is part of the process of wrapping the primary up.

The statement also has an impact, of course, on the press, which will dutifully run a bunch of “Is it over?” stories. It was over yesterday, and it is still today. (Like Franco, Rick Santorum’s campaign is still dead.) That drumbeat and the reaction of voters who are also anxious to take on Obama may accelerate the process.

But if not, and Santorum stays in, what difference does it make? If he keeps losing and, as he did last night, remains positive (not tearing Romney down), there’s no harm in him remaining in. At least no harm to the GOP. His own reputation and career are another matter.