When Sen. John McCain fires up the grill this weekend, at least according to the New York Times’ Adam Nagourney, there will be some very special guests lining up for burgers. The campaign has a firm policy of not talking about the vice presidential selection process, but it seems that this shindig may be a part of it, since three “short list” possibilities are on the guest list.

We should also note that, while the NY Times article doesn’t mention it, CNN is reporting that Mike Huckabee was also invited for the weekend get together, but had to decline due to a previous engagement.Today I’ll be taking a look at these possible selections and evaluating their strong and weak points.

Senator John McCain is planning to meet this weekend with at least three potential Republican running mates at a gathering at his ranch in Arizona, suggesting that he is stepping up his search for a vice president now that the Democratic contest appears basically decided, according to Republicans familiar with Mr. McCain’s plans.

Gov. Charlie Crist of Florida, Gov. Bobby Jindal of Louisiana and Mitt Romney, the former governor of Massachusetts and a one-time rival for the Republican nomination, have all accepted invitations to visit with Mr. McCain at his ranch in Sedona, these Republicans said.

First, let’s take a look at Charlie Crist. The Florida governor is an obvious possibility. He’s very popular in the Sunshine State with cross party appeal. At 51, his relatively young age is a good match for the 71 year old McCain and could be well positioned for a presidential run of his own in 2012 or 2016. My only real question on Crist is, does McCain really need him to land Floiday in November? Obama is already struggling there, having trouble reaching out to the Hispanic vote as well as the older, white voter base. Current polls show Obama trailing McCain by ten points in Florida and some Democratic strategists already fear that the Illinois senator may have to write that state off and make up the 27 electoral votes elsewhere. Plus, if the Democrats don’t find some way to seat their delegates at the convention, Florida may not be in play for them anyway.

Mitt Romney may also seem to be another obvious choice, but his problems as a potential running mate are legendary as I see it. Mitt was the darling of hard core conservative leaders and talk radio voices who, surprisingly, considered him the “real” conservative choice despite his many years of more liberal positions as the Mass. Governor. But even given that vocal support, and massive funding, Romney was unable to close the deal with voters in the primary. There is also still the factor of his religion. Voters seemed to indicate that they simply were not ready to vote for a Mormon, regardless of his affable personality. Geographically, Mitt brings nothing to the ticket as he’s not going to turn Massechusetts red in November.

Jindal is certainly one of the most interesting choices. He is a new, young, up and comer with an “exotic” background and has generated a lot of excitement. He’s even been described as a sort of GOP Barack Obama. Also, Obama has been showing signs that he might have some solid popularity in Jindal’s home state of Louisiana, and Jindal could counter that. The problems with Jindal as the veep pick are numerous, though. First, there is his age. Particularly given McCain’s advanced years, his vice presidential pick will be under a lot of scrutiny in terms of “being ready on day two” in case of disaster. The Louisiana Governor is 36 years old, only one year older than the bare minimum to be president and may not be viewed as having the maturity and experience for the job. And while it may not be spoken of much in the old media, Jindal will certainly face some demographic challenges. Jindal’s parents immigrated here from India shortly before he was born. The GOP has had a long history of problems when it comes to minority candidates. This year they fielded ten white males as presidential hopefuls, and there is no longer even a single black Republican in Congress. If the Democrats (traditionally viewed as the more “diverse” party) are having trouble getting their white base voters to line up for Barack Obama, how excited will McCain’s base be about supporting an Indian to be a heartbeat away from the presidency? Plus, Jindal was born a Hindu, later converting to Christianity when he was a teenager. We’ve already seen the whisper campaigns against Obama from people who falsely suspect that he is (or once was) a Muslim. Will Republican voters overlook Bobby’s background as a Hindu? McCain will have to take all these questions into consideration.

The man not at the party this weekend may still turn out to be the best choice. Huckabee enjoys wide popularity, particularly throughout the south where Obama seems to be more competitive than other recent Democratic candidates. His conservative credentials appear solid and could bolster some of the base who remain skeptical about McCain’s bona fides in that area. He is also in the right age range… old enough to be seasoned while young enough to be viable in four or eight years.

Who will John McCain pick to come along as his prom date? Only the nominee knows, but I imagine we’ll find out well ahead of the convention.