Mitt Romney is in danger of losing his home state next Tuesday.

The former Massachusetts governor is on bad terms with numerous rank-and-file Republican voters in his own state, the result of the widely-held perception that Romney essentially abandoned them halfway through his governorship.

The Massachusetts Republican universe is small -- less than 15 percent of voters are party members -- and turnout in next Tuesday's primary could be comparatively microscopic, particularly if independents vote in the Democratic primary. Polls have shown Romney leading John McCain, who won the state overwhelmingly against George W. Bush in 2000, by about 15 points.

But those surveys were conducted before McCain's recent string of successes. Now, even Romney's top Bay State backers are admitting that defeat is at least possible. "Senator McCain will probably run well in the Northeast. Governor Romney will run well around the country," former Massachusetts Governor Bill Weld, a Romney supporter, told the Boston Herald today.

The fact that Weld is doing spin for Romney pretty much explains Romney's precarious position in his home state, where no other big name Republicans have endorsed their former governor. Paul Cellucci, the governor from 1997 until 2001 (and Weld's lieutenant governor for six years before that) snubbed Romney for Rudy Giuliani. So did Joe Malone, who won statewide elections as Treasurer in 1990 and 1994 (and who once mounted a spirited challenge to Ted Kennedy), and Jim Rappaport, who chaired the state G.O.P. in the Weld years. And Jane Swift, who inherited the governorship from Cellucci in 1997, is backing John McCain. (Swift was pushed out of the governorship by Romney in 2002.) Three of the five Republicans in the State Senate have also declined to back Romney.

For Romney, that pretty much leaves Weld, who is considered something of a traitor by the Massachusetts G.O.P. After abruptly resigning the governorship in 1997, he left his family in Cambridge and moved to Manhattan, eventually remarrying and -- after trying to reinvent himself as a social conservative -- waged a disastrous bid for the Republican gubernatorial nomination in New York two years ago.

More than a few Massachusetts Republicans see Weld and Romney as two peas in a pod. After riding to the state party's rescue in the 2002 gubernatorial election, Romney soon quickly set his sights on national office and spent the latter half of his term awkwardly distancing himself from the positions and attitudes he espoused en route to his '02 triumph. He tirelessly traveled the national G.O.P. circuit, cracking jokes at his home state's expense ("San Francisco East!" he proclaimed at last winter's Conservative Political Action Conference) that invariably made their way back to the Massachusetts media. His popularity plummeted in 2005 and 2006 and was a contributing factor in Republican (and Romney's lieutenant governor) Kerry Healy's 20-point loss to Deval Patrick in 2006 -- a loss that locked the party out of every single Constitutional office in Massachusetts for the first time in decades.

The last major presidential candidate to lose his home state in the primaries was Jerry Brown, who lost California to Bill Clinton in 1992, 49-40.

Previous Massachusetts candidates have had no trouble winning their state in the primary season: John Kerry in 2004, Paul Tsongas in 1992, Michael Dukakis in 1988 and Ted Kennedy in 1980 all cruised to victories. A much different fate may await Mitt Romney next Tuesday.