Newt Gingrich claimed the South as his native land in Monday’s debate, but so far it’s a Northeasterner who’s racking up the endorsements of southern governors.  Today, Virginia’s Bob McDonnell joined South Carolina’s Nikki Haley as endorsers of Mitt Romney.  McDonnell will also join Romney and Haley on the campaign trail:

Gov. Bob McDonnell this morning endorsed Mitt Romney’s bid for the Republican presidential nomination, calling him a “results-oriented conservative” who can appeal to Democrats and independents.

McDonnell, making his choice known on the eve of the hotly contested South Carolina primary, said on CNBC’s Squawkbox that he will tell voters there that Romney has the best chance to beat President Barack Obama in November.

“My message will be if you want to win the race in November, vote for Mitt Romney,” McDonnell said. “He can win Democrats and independents to our cause.”

McDonnell is in New York City this morning for a state-related economic development meeting, but will fly to South Carolina this afternoon to join Romney, South Carolina Gov. Nikki Haley and others at a rally in Charleston. He will travel to Greenville with Romney for a campaign event tonight and stay for a Saturday morning event before returning to Richmond.

The Times-Dispatch considers this an inevitable choice by McDonnell.  With Perry out of the race, Romney is the last governor standing, and since McDonnell helms the Republican Governors Association at the moment, gubernatorial experience weighs heavily on his choices.  McDonnell has said as much publicly, advising voters to look for a candidate with state-level executive experience, and Perry’s exit leaves McDonnell only one opportunity to take his own advice.

Not that Romney will mind much that it took a default to get McDonnell’s endorsement.  With Gingrich gaining on him, Romney needs all of the high-profile endorsements he can gather, especially in the South.  McDonnell had been popular among conservatives when running for office in 2009, along with Chris Christie in the unusual off-year cycle.  McDonnell has a quieter approach than Christie but has governed more conservatively.  He has used his veto to sharply restrict state funding for abortions, and his proposal to end the state’s monopoly on liquor stores has more libertarian-minded conservatives cheering as well.

How much will this help in South Carolina?  It comes a little late in the primary schedule for it to have a lot of impact, but McDonnell may have more impact in Florida.  I’d expect to see a lot of him next week as Romney tries to get his campaign either back on track or heading for the home stretch with a big win in the Sunshine State. McDonnell might also be a consideration for Romney as a running mate in the general election, if Romney manages to win the nomination, as a man who could help attract conservatives without overshadowing the top of the ticket.