The death of Senator Frank Lautenberg has given New Jersey's governor an interesting choice. Who will Chris Christie appoint to fill the vacancy, and what will it mean for his own political future?

Christie has already announced that there will be a special election this October for the seat, no matter who he picks to fill the seat in the meantime. This is nothing short of sheer political opportunism on his part, because if he weren't scared that this race might impact his own re-election bid for governor, he could quite easily have put this race on the ballot which takes place a bare few weeks after the special election. New Jersey voters will go to the polls mid-October, and then in early November -- costing the state over ten million dollars. That's a dandy point of attack for his Democratic opponent, one would think. But that choice has now been made, and it's kind of beside the point here.

Christie remains popular in New Jersey, one of the rare Republicans who can keep a blue state happy. Which is why he's got to be assessing his chances of a run for the White House in 2016. Seen through this lens, Christie's got three basic choices to fill the empty Senate seat before October, and it will indeed be interesting to see which one of these he picks.

Name a Republican who will not run to keep the seat

Christie's "safe bet" would appear to be naming some caretaker Republican who would not run to keep the seat beyond October (either in the special election or in the 2014 election, when the seat will be up for grabs again). He could nominate some "old bull" from the party, or some loyal staffer who would promise not to run in the future. This is an accepted "polite" thing to do in these situations, and it has been done recently by both Republican and Democratic governors. By doing so, Christie would send the message that the voters are the ones who get to make the ultimate choice and there should be no "stacking the deck" before that happens.

This will probably be popular in New Jersey, a state which hasn't actually elected a Republican to the Senate since bell bottoms were in fashion. Democrats wouldn't fault Christie for replacing a Democrat with a Republican if the nominee showed no interest in campaigning to keep the seat. On the national level, Christie would get points from Republican primary voters for denying Harry Reid a Democratic vote for most of the rest of the year. At the very least, they wouldn't punish Christie for doing so, one assumes, as long as the nominee is fairly non-controversial.

Name a Republican who will run to keep the seat

This would be the choice to really please the Republican Party primary voters, though. Christie's always been seen as a fairly hardball type of guy in politics, and this would burnish this reputation. Christie could name and up-and-coming Republican who was already planning on running for the seat in 2016, and by doing so give that candidate a leg up by being able to run as a sitting Senator.

While this would please the national audience of Republican Party primary voters (who may determine Christie's ultimate fate in 2016, of course), it might leave a bad taste in the mouths of New Jersey voters (at least, the non-Republican ones). This could damage Christie's brand of being a "fair and square" type of politician, and give him headaches in his re-election campaign. If Christie lost the governor's race this year (a longshot, but worth mentioning), it may take the shine off him as a candidate in 2016. He certainly would have a much lower profile if he wasn't in the governor's office for his presidential run.

Of course, Christie may think he'll win re-election anyway (and he may well be right to think so), and if he chooses this route it will be very interesting to see what sort of Republican he appoints -- a Tea Partier, or a mainstream candidate?

Name a Democrat

This is probably not a very high probability, but it could conceivably happen. Christie has never been particularly afraid of promoting himself as being somewhat "above politics" -- especially since his embrace of President Obama in the post-Sandy era.

He could conceivably announce that New Jersey voters have long sent Democrats to the Senate, that the senator who died was a Democrat, and that he will respect the wishes of the voters by naming someone not of his party to finish out Lautenberg's term. I can see him making that announcement (whereas I couldn't see many other Republican governors ever doing so) -- it's within the bounds of possibility. Christie would boost his own approval among Democratic voters in New Jersey, since it would be seen as such a selfless move, politically. "Rising above partisanship" and all of that, to put it another way. So -- within his state, at any rate -- naming a Democrat might be beneficial to Christie himself among the voters.

Of course, by doing so he could also use the situation to his advantage as well. Christie could pick a Democrat who is not named "Cory Booker," and thus set the cat among the pigeons for the Democratic primary for the special election. By raising some Democrat's profile in the race, he could ensure a very close primary contest which would force Booker (who really, really wants to be senator, and has for quite a while) to spend a lot of money in the primary -- making it easier for whomever gets the Republican nomination.

That's pretty Machiavellian, however. And it ignores the wider (national) implications of Christie naming any Democrat -- the fact that it might absolutely kill his chances of ever becoming the Republican nominee for president in the future. It may be a "deal-breaker" for Republican primary voters, who are not generally considered a very forgiving bunch. They would see it as nothing short of a traitorous move to the Republican Party's chances, and they would likely not reward such a man with the nomination for higher office. This alone means Christie will very likely not nominate a Democrat (unless, of course, he really isn't all that serious about running for president anyway, which is also a possibility many fail to consider).

-- Chris Weigant

Follow Chris on Twitter: @ChrisWeigant