It was just six short weeks ago, right before the Iowa caucuses were mistakenly called for Mitt Romney, that I saw former Sen. Jim Talent in the halls of the Hotel Des Moines. He was a top Romney surrogate, so I asked him: What did he make of Santorum’s good showing there?

“Rick’s a good speaker,” Talent shrugged. “I just think we’ve got the candidate with the background and the ability to beat Obama. Everybody up there checks some boxes, but Romney checks ‘em all.”

Talent had served with Santorum in the Senate. What had he learned about him that should give voters pause?

“I’m not going to trash Rick,” he said. “I’m very happy for him. I just think we’re the ones that won tonight – anything that’s close is technically a tie, and everyone else had to beat Romney.”

The race went on. Santorum, surprisingly, became Romney’s most credible rival. So the Romney campaign held two surrogate conference calls today, giving Idaho’s Gov. Butch Otter and Missouri’s former Sen. Talent (and others) space to trash Santorum. Talent did what he’d refused to in January: He criticized Santorum for supporting Medicare Part D. And then a reporter on the call pointed out that Talent had supported the same bill.

There may be a parable here, illustrating just how rote the Romney machine has become, or how tricky it’ll be to find the weakness in Santorum’s campaign to send a TIE Fighter in to shoot at.

