All state primaries are not created equal. But in some of them you must declare your party affiliation, and thus get to vote only for candidates in that party. In effect, that makes it impossible to vote for a candidate you happen to favor in one party if you declare in the other one. But it also creates an interesting opportunity for voters to cross over to the other party when it is convenient to do so in primaries, without affecting how you will be able to vote in the later general election.
What that amounts to is a golden opportunity to help shape the "other" party's candidates even before they get to the general election. Here is a chance to help eliminate the obstructionist Tea Party element from even getting to the ballot in the general election.
Voting this way can have some distinct advantages, but there may be some drawbacks to consider. If, for example, there is a primary race of importance in the Democratic primary, then you may want to forgo this strategy. But if the ink is pretty much dry on the Democratic ticket in a Red State, then helping to shape the look of the Republican ticket is all that much more important from a practical logistics point of view.
Simply go to a Tea Party website that is vocal about who they support, copy and print their list of favorites, and take it into the booth with you on Primary day. Look for those names and cast your vote for anyone else running in opposition to them. Especially look for alternatives who are known moderate incumbents. It's just that easy.
There is no illusion here that enough left-leaning voters will turn the election, but the fact remains that the Tea Party gathers and maintains its stranglehold on the GOP largely because Republicans see bucking them as significantly counter-productive. If Tea Party candidates sweep into office with a striking majority of the vote, this impression is intensified. If they barely squeak in, or better yet, are actually defeated in many election results, the GOP will see that the Tea has begun to go rancid. The stranglehold will release. Moderate Republicans will gain back some of their spine. The world will be a better place.
So, do your part in those Red State primaries. Give the GOP back to the moderates by helping to vote out those obstructionist right-wing radicals who have taken hostage that which used to actually be a Grand Old Party.
March 4 is primary day in Texas, and I have my list printed out. Do your part. Vote! (Even if it is for people you don't actually want to be elected.)