As somebody who has always lived in blue states, I’ve never been able to cast a vote in a presidential election that had any bearing on the outcome, making me struggle with a question of whether it’s even worth voting — especially since I always have problems with the Republican nominee. In this election, however, given the closeness of the popular vote, there is a compelling reason for conservatives to turn out to vote, even in states where there isn’t a competitive presidential, Congressional or Senatorial race.

If President Obama is reelected on Tuesday, he’ll do his best to claim a popular mandate for his agenda. Pundits will be claiming that Tea Party extremists cost Mitt Romney the election and the usual suspects will be urging Republicans on Capitol Hill to acquiesce to Obama. This will have immediate consequences during the end of the year “fiscal cliff” negotiations. However, if Obama loses the popular vote, he’ll be in a much weaker position going into these negotiations and Congressional Republicans will be emboldened to continue to resist Obama in his second term.

Just two days out from the election, it’s still plausible that Obama could win a narrow Electoral College victory while losing the popular vote. Three things are making that possible: 1) Romney is racking up wider margins than McCain did in red states 2) Swing states are a lot closer than they were four years ago and 3) Polls show Obama’s margin in blue states shrinking, in some cases dramatically. The third point is the most relevant to the subject of this post.

It’s very hard to try and get a sense of where the race is in most noncompetitive blue states, where there hasn’t been as much polling. Also, it’s hard to know how overall turnout in those states will compare to 2008 if turnout for Obama is down. But just as a rough experiment for the purposes of this post, I looked at a handful of blue states in which Obama racked up huge margins in 2008, and I adjusted the margins to reflect current state polling the Real Clear Politics average. For instance, in 2008, Obama won California by a 24-point margin, or 3,262,692 votes. In the current RCP average, that margin is down to 14 points, which applied to the same turnout level in the state, would reduce Obama’s raw margin in the state by nearly 1.4 million votes. Repeat the exercise with Massachusetts, Illinois and Maryland, along with the much closer Michigan, Wisconsin and Pennsylvania, and it would translate into a difference of 3.5 million votes, or over one-third of Obama’s national victory margin of 9.5 million votes. This is from just seven states, and assumes Romney doesn’t pull off upsets in Michigan, Wisconsin or Pennsylvania.

No doubt, it wouldn’t be hard to take issue with some of the assumptions made in this calculation. As I cautioned, it is very rough. But it does help demonstrate my main point, which is that with the national vote this close, there’s still a compelling reason for conservatives in blue states to vote even if Romney isn’t contesting them.