Last week, Tom Tancredo signaled he was ready to exit from the national spotlight since others were taking up his cause of fighting against the creation of a lawful, permanent presence for the undocumented among us. I was skeptical. This week, he's ready to step into the ring against Senator John McCain in the presidential primaries.

"If there are candidates who are diametrically opposed to what we're trying to accomplish here, and if there's anything I can do to retard their progress, I will do so," he told The Associated Press, acknowledging that McCain meets that description.

The possibilities are intriguing. Here's one: Tancredo takes votes from McCain and the Republican candidate ends up being a pro-choice, non-xenophobic, non-homophobic fiscal conservative who favors a troop pullout now. Is there such a candidate?