Rick Santorum getting out of the race for president presents two interesting problems in Texas. First, he'll be on the Republican primary ballot anyhow — it's too late to get off. Second, without a fight at the top of the ticket, turnout will probably slide.

Who benefits? It's hard to get a straight answer. The campaigns are all in the sales business, basically, and they're all full of reasons why lower turnout would benefit their candidate, whether that candidate is a social conservative, a moderate, an incumbent, a challenger, a dog or a cat.

Turnout in 2008 — a banner year, in comparison — was sort of a stinker. Just 7.7 percent of the voting age population showed up for the Republican primary and 16.2 percent showed up for the Democratic primary (a fight that year between Hillary Clinton and Barack Obama).

In a state where the Republican primary was the only real challenge to anyone seeking statewide office, fewer than 682,000 votes were all it took to win. John McCain won in Texas that year, but just cleared the halfway point, with 51.2 percent of the vote. Former Arkansas Gov. Mike Huckabee, for all practical purposes out of the race by then, got 38 percent in the GOP primary here. With the battle on the other side, it took more than 1.4 million voters to win a Democratic nomination.

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That was in a year with a bigger than normal turnout. Now the political world is full of spin and gossip about who will vote. Old people? Hard core activists? Which kind of hard-core activists? Tort reformers? Social conservatives? Tea partiers?

It's safe to say the uncertainty makes people nervous. But the candidates have relatively good lists of people who always vote in Republican primaries and for bond elections and such. They have reasonable maps that show local races could gin up significant local interest in places like the suburban counties south of Houston, in Collin and Tarrant counties were there are more than one hotly contested races, and so on.

And they know this: People are voting early more than they used to. One experienced consultant in a Senate campaign is predicting more than half of the voting will be done before Election Day. That can be read as an argument for early spending on ads — whether they're on social media, the internet, TV, radio, 4x8s, cable, door hangers, yard signs, sound trucks, bumper stickers emery boards, funeral fans, combs, or whatever you want to imagine.

The election is just over six weeks away. Early voting begins two weeks before that. A couple of candidates have already started ad campaigns that probably won't stop until the voting is over. They're trying to excite an electorate that, with a late date following a holiday and no fight at the top of the ticket, could be shrinking to a small and unpredictable size.

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