While the oft-insightful Quin Hillyer deserves a lot of credit for noticing early on that Rick Santorum’s potential in the GOP primary was deeply underrated, his rooting interest seems to be blinding him. Contra Quin, this has not been a good week for Santorum’s campaign. Santorum is still ahead in national polls, but his lead has narrowed slightly. In Michigan, his lead is gone — Mitt Romney has the momentum. Santorum never led in Arizona, but he was gaining on Romney for a while; Romney’s lead has recently grown. The reason is obvious: Santorum’s debate performance was, as Ross Kaminsky said, disastrous, as most observers (but not Quin) could see plain as day. It would be foolish to write Santorum’s obituary at this point, but to say he’s gaining based on kind words from John Hawkins and an endorsement from Robert Aderholt — not exactly a backbencher, but hardly a high-profile voice in the current House — seems divorced from reality.