There has already been considerable speculation about how the presidential race could affect Tom Craddick’s effort to hold onto the speakership–namely, that if Hillary Clinton is the Democratic nominee, she will be a drag on the Democratic ticket in downballot races in the general election. (Republican pollster Mike Baselice, in a presentation to the Texas Association of Taxpayers, said that he had found no statistical evidence of the presidential race having a downballot impact, but there is a long way to go before election day.) However, it is possible that the presidential race could affect the March 4 primary elections as well.

Keep in mind that one of the big surprises of the 2006 primary elections was the impact of Texas Parent PAC. As Harvey Kronberg has written, “A group of committed activists capable of rallying non-traditional constituencies can have a disproportionate effect in modest or low turnout House race primaries. [Parent PAC] was able to rally anti-voucher, pro-public school supporters and turn them out in key GOP legislative contests.”

Parent PAC was able to mobilize Democrats in the education community to cross over and vote in Republican primary races for candidates the organization had endorsed. These voters were responsible for the defeat of Public Education committee chair Kent Grusendorf and helped elect pro-education Republicans against Craddick-backed candidates.

But the presidential primary, which will be on the ballot along with state and courthouse races, could change voting patterns. Here are a couple of scenarios:

* The Democratic presidential nominee is not known on March 4. Pro-education Democratic voters may decide to stay home and vote for the presidential candidate of their choice rather than vote for candidates who carry the Parent PAC endorsement in the Republican primary. This would be a huge advantage for Craddick. Some pro-education Democrats may stay and vote for their candidate even if their party’s nominee is known.

* The Republican presidential nominee is known on March 4. This could depress Republican turnout. That, of course, would be a disadvantage to Craddick, as it would give the votes of crossover Democrats more impact.

The conventional wisdom is that it’s going to be hard for either party to pick up seats in November. That makes the primaries all-important. The big harvest in the speaker’s race is in the Democratic primary, where several seats held by Craddick Ds could be won by mainstream Ds (Baily, Pena, Puente’s open seat are the obvious targets; Flores also has a primary opponent). The upcoming special election to fill the seat left vacant by the retirement of Anna Mowry is a swing race with seven candidates, only one of whom is a Democrat; fundraising frontrunner Craig Goldman has pledged to Craddick; former member Bob Leonard, endorsed by Mowery, has not).