Let’s be fair to Barone. Some of his congressional district numbers were meaningless—Bush flipped some districts in New York, New Jersey and Connecticut entirely because of 9/11, and it was foolish to believe that, say, pro-choice voters in Long Island were going to keep voting Republican. Also, it was a bit much to imply (as Barone did here and pundits like Hugh Hewitt did elsewhere, at greater volume) that states like Ohio and Florida and Colorado should be sending two Republican senators to Washington just because they narrowly went red.

But Barone, like Bush, is a supporter of immigration and a supporter of comprehensive reform. Bush’s outreach to Hispanic voters was an incredible boon to the Republican party, and in 2005, there was reason to believe it would continue. For example, Bush narrowly carried California’s 47th Congressional District, which is 65 percent Hispanic. If the progress that Republicans made with Latino voters in 2000 and 2004 continued, the party would have been more competitive in the Southwest. Not many people (unless they closely study talk radio) saw the immense base backlash to immigration reform coming in 2006, or predicted that it would be successful in scuttling a bill. The result of that: a huge chunk of the Latino vote moving from Republicans to Democrats.

Barone’s theories—he has a new one today about upscale voters—depend on the GOP discovering a tolerance that doesn’t exist in some segments of its base. That’s why he was wrong in 2005.

William Milliken, a former Republican governor of Michigan, seemed to walk back his previous endorsement of McCain in an interview yesterday with The Grand Rapids Press.

“He is not the McCain I endorsed,” said Milliken, reached at his Traverse City home Thursday. “He keeps saying, ‘Who is Barack Obama?’

I would ask the question, ‘Who is John McCain?’ because his campaign has become rather disappointing to me.

“I’m disappointed in the tenor and the personal attacks on the part of the McCain campaign, when he ought to be talking about the issues.”

Milliken, a lifelong Republican, is among some past leaders from the party’s moderate wing voicing reservations and, in some cases, opposition to McCain’s candidacy.

Milliken stopped short of endorsing Obama, unlike Michigan Republican Phil Arthurhultz, a former state senator, who appeared with former Sen. Lincoln Chafee (R-R.I.) in Grand Rapids to support Obama.

Milliken illustrates the risk McCain is running by attacking Obama’s character. While it may stir up the base and increase conservative turnout — which worked for President George W. Bush and Karl Rove in 2004 — it seems unlikely to work this time.

Obama has broad appeal to independents and, apparently, moderate Republicans.

My colleague Sridhar Pappu wondered yesterday how this race would be shaping up if McCain had selected Sen. Joe Lieberman (I-Conn.) for his vice presidential nominee. He probably wouldn’t have to worry about swing-state moderates fleeing his own party.