Michael Gerson’s lament over Republican weakness in New Mexico misses something:

Yet President George W. Bush won New Mexico (barely) in 2004 — one of two states that flipped from the Democratic to the Republican column. Now Romney is not close to competing.

Notice that Gerson writes about Republican woes in New Mexico as if the 2006 and 2008 elections never happened. Bush did barely carry New Mexico, just as he barely won re-election. New Mexico has voted for the winner of the popular vote in almost every election since statehood, and until 2008 the winner’s share of the vote in New Mexico was close to the national result. Something changed between 2004 and 2008, and New Mexico went from being a competitive state for both parties in presidential elections to becoming a very Democratic-leaning state. Obama received almost 57%. One explanation for this is that a large majority of New Mexicans reliably vote for Democrats for most statewide offices and the state legislature, and now they are voting for Democratic candidates in federal elections in the same way. What that doesn’t tell us is why this started happening.

The erosion of the Republican position in New Mexico coincided with Bush’s disastrous second term, which happened to be the period when Bush made his biggest push on immigration legislation and when the Republican Party nominated its best-known supporter of amnesty as its presidential candidate. It would be a mistake to conclude that the GOP lost ground in New Mexico because of those things, but it’s important to remember that Republicans have already run a presidential candidate with Gerson’s preferred views on immigration and lost in New Mexico by 14 points. Of course, McCain lost the election, so he should have failed to carry New Mexico, but what’s remarkable about the margin of loss in New Mexico is how much worse it is than the national result.

McCain hailed from a neighboring state, and he had a long record of advocating for a more liberal immigration policy. If Gerson’s recommendation made sense as a matter of politics, McCain probably should have received more support in New Mexico than he did nationally. Instead, he received just 42% of the vote in New Mexico, and only 30% of Hispanics supported him. That suggests two things: many Hispanics in New Mexico fled from the GOP just as many other former Bush voters did because of the failures of the Bush administration, and putting forward a candidate with well-known pro-immigration views didn’t halt that.

Curiously, Gerson invokes Gov. Martinez’s popularity in New Mexico in order to contrast it with how unpopular Romney is in the state. He fails to mention that Martinez won the Republican gubernatorial nomination in 2010 in no small part because she presented herself as the more conservative candidate on immigration, and accused her main rival Allen Weh of being a supporter of amnesty. She didn’t abandon that position during the general election campaign. She campaigned on immigration in exactly the way that Gerson says that Republican must not campaign, and she won.

That suggests that Romney’s problem in New Mexico isn’t primarily his position on immigration, but rather his affiliation with a national party that is still deeply unpopular and still recovering from the damage done to its reputation during the Bush era. Put another way, Romney could mimic George W. Bush on immigration as McCain did and still have no chance to carry New Mexico, because New Mexico wasn’t lost to Republicans at the federal level mainly because of immigration. It was lost because of the overall disastrous record of the Bush administration. Don’t expect to hear that from Gerson anytime soon.