Conservatives downplayed it as a #MarcoBoat, and pointed out that $80,000 is a tiny fraction of the six- and seven-figure conflicts of interest that populate stories about Hillary Clinton.

But I noticed that it was flogged a bit by immigration hawks like Ann Coulter and Michelle Malkin. It’s a reminder that Rubio’s problem may not be his character, but his position on immigration reform. The hard-core immigration hawks in the Republican Party have not bought into the image Rubio is trying to sell, of a politician who was chastened by his failure in securing comprehensive reform. And that can cost him.

Mitt Romney neutralized Rick Perry on this exact issue four years ago, saying that Perry had created magnets for illegal immigrants by providing their children with in-state tuition. He baited Perry into repeating the liberal’s criticism of immigration hawks, with Perry claiming that they “don’t have a heart.” More than anything — even the “oops” moment — this is what brought down Perry’s campaign.