I generally see my job here as covering the campaigns, not giving them advice, but I can’t help but note when one has let a golden opportunity slip through its fingers. (If it’s any consolation, I figure this posting will irritate the McCain and Romney campaigns equally.)

The response from Team Romney to McCain’s jab on the conference call was pretty weak tea, from where I sit. On that same conference call, amidst his passionate defense of the immigration reform deal, McCain admitted he had not heard that the bill had removed any requirement that an illegal immigrant pay back taxes. (The previous version had required illegal immigrants pay back taxes for either two out of three or three out of five years. Kaus has all the details.) McCain said he believed that paying back taxes should be a requirement.

Imagine how Team Romney could have used this: Why is John McCain defending a bill when he hasn’t read through all of its provisions? How can he urge his fellow senators to vote for it when he’s not familiar with everything in it? Why is he urging them to pass a bill when it includes provisions that he specifically opposes, such as amnesty for all back taxes? How can he say this bill isn’t an amnesty when it includes an amnesty for back taxes? And so on.

Americans don’t like paying their taxes. They really don’t like the thought that an illegal immigrant might get a sweeter deal in getting out of paying taxes than they do. This is a lead pipe of an issue for opponents of this bill, and right now, nobody on the campaign trail is picking it up.

BONUS: For any candidate who wants to establish independence from President Bush… here’s your issue! The White House demanded this requirement be taken out of the bill!