Vote or Die.

I'm not yet convinced which of the candidates (if any) should be President next year. So why am I only allowed to vote in one primary tomorrow (Virginia)? I want to vote in BOTH the democratic and republican primary- I think that's fair. I understand a bunch of nearsighted old guys made up this rule a while ago to force people to choose a side. But I'm not ready to choose my President or even decide which "side" I'm voting on. Don't they all mush together these days anyhow?

People who read my blog: why can I only vote in one primary? Who decided this?

Update: Why can’t I vote in both primaries or vote for candidates from different parties?
Virginia is an open primary state which means that any qualified voter can vote in either party's primary election. Virginia does not have party registration in its voter registration process. In other words, citizens do not designate a political party affiliation when registering to vote in Virginia. Virginia election law stipulates that while any qualified voter may voter in either political party's primary election, no voter may vote in more than one political party's primary on the same election day...