When I first read this Associated Press report, the first thought that came to mind was, “Didn’t former President George H. W. Bush already endorse Mitt Romney?”  Actually, no, at least not formally, but that’s a fine distinction.  By tomorrow, that distinction will be erased:

Former President George H.W. Bush plans to endorse Mitt Romney, further urging the Republican Party to coalesce around the former Massachusetts governor’s presidential campaign.

Romney spokeswoman Gail Gitcho says the two will meet Thursday in Houston. They plan to appear together and speak to reporters.

Formal backing from the 41st president shows the Republican Party is uniting behind Romney while pressure builds on challengers Rick Santorum and Newt Gingrich to leave the race.

On one hand, I share Allahpundit’s reservations on just how meaningful this will be to those who oppose Romney’s nomination.  While Bush 41 did a fine job as President, he left a bad taste in the mouths of conservatives over his tax-hike deal in 1990, after his “read my lips” promise to oppose tax increases.  Democrats never delivered the promised spending cuts, either, which made him look weak, and Bill Clinton mercilessly exploited that in the 1992 election.  It’s difficult to see how this endorsement will move the needle now — with all else being equal.

The question will be whether all else is equal at the moment.  Back in December when Bush expressed support just short of an endorsement, Rick Santorum had begun vaulting up the polls and Newt Gingrich was still competitive.  At the moment, the two most likely outcomes appear to be Romney winning a majority of delegates by June, and Romney winning a brokered convention thanks to his delegate advantage and sotto voce alliance with Ron Paul.  An endorsement now might push the nomination process towards that tipping point where everyone just decides to get on the bandwagon and finish the primaries in order to focus on the fall election.