I said this morning that a Tancredo endorsement of Romney would be hard to believe. It still is- except that it is exactly what Tancredo chose to do. This makes sense only if Tancredo wanted to make sure he endorsed someone with a good chance at winning the primary and decided that, in fact, Fred Thompson has no shot at winning the primary. Certainly if Tancredo limited his options to the top four candidates, Romney is probably least uncredible on being anti-immigrant (yes, that's a triple negative-deal with it!). But that's a very low bar given Giuliani's even-more recent than Romney conversion to getting tough on illegal immigrants, Huckabee's generally sympathetic view of immigrants, and McCain's relatively pro-immigration stance (which is closest to my own).
Had Tancredo endorsed Thompson, Thompson probably catapults into contention for a respectable showing in Iowa, especially since Tancredo was apparently pulling a somewhat-respectable 6% in Iowa in the most recent Des Moine Register poll. This would have had the tangential effect of keeping immigration a hot topic in the race, since Thompson could have really hit home on the issue.
By endorsing Romney, Tancredo probably reignites Romney's chances at winning Iowa, significantly wounding Huckabee in the process. He also gives Romney instant credibility on the immigration issue. On the other hand, Romney remains vulnerable enough on immigration thanks to his personal illegal immigrant scandal that it's tough to see Romney making immigration a focal point of his campaign. The endorsement also takes away much of Thompson's ability to attack Romney's credibility on illegal immigration.
So, in some ways, Tancredo's endorsement of Romney may be counterproductive to Tancredo's single-issue fight because it probably makes the issue of attacking illegal immigration less important to the overall primary battle now.
At the same time, it is getting impossible to see the Thompson campaign making any kind of turnaround. I'd be surprised to see him hang around past South Carolina.
**UPDATE** It appears Tancredo's biggest mission was to stop the Huckster (and maybe McCain):
“While several of the candidates appear to be committed to our cause, there are others whose records as public servants are abysmal on this issue. They have been on the other side of the battle for years and encouraging and even inviting, in a way, illegal immigrants into the country. I fear that remaining in this race, when I know I cannot win, could contribute to the nomination of one of those candidates. We have done too much. We have come too far. The stakes are way too high for me to allow that to happen.”
Still, I think this endorsement has the net effect of reducing the impact of the illegal immigration issue on the post-Iowa race.