In tonight’s Texas primary, President Obama faces another set of red-state voters — and with it the possibility that some little known challenger could wrack up some significant portion of the Democratic vote.

Challenging Obama for the Democratic primary nod will be John Wolfe, the Tennessee attorney who took over 40 percent of the primary vote in Arkansas, Florida author Darcy G. Richardson and Chicago investor Bob Ely.

“I think the President might have some protest votes against him in the Texas Democratic primary today,” said Harold Cook, a veteran Democratic strategist in the state. “Many conservatives here vote in the Democratic primary, driven mostly by local contested races.” But he added, the vote has “absolutely no significance for November.”

Matt Angle, another expert on Texas Democratic politics, concurred. ”In Texas, the people who don’t like Obama vote in the Republican primary,” he said.

A look at the numbers suggests that Obama will perform better in Texas than in Arkansas, Kentucky and West Virginia — all states where he lost upwards of 40 percent of the Democratic primary vote. Even so, the Lone Star state could still cause the Obama campaign a bit of heartburn.

Here’s why that protest vote will likely be smaller than it was in those three primaries.

* Antipathy towards Obama in Texas does not go as far back as it does in those other states. In the 2008 Democratic primaries Obama nearly tied Hillary Clinton in Texas and won the state’s subsequent caucuses. Clinton won overwhelmingly in Arkansas, Kentucky, and West Virginia.

Obama is not as unpopular in Texas as he is in the three states where he has performed poorly, according to Gallup. That said, his approval rating in the state is still below the national average. A recent Texas Tribune/University of Texas poll found Romney beating Obama in Texas by twenty points. (In 2008, John McCain won the state by 12.)

* Turnout in Arkansas and Kentucky was quite low. With several high-profile primaries in Texas, turnout is expected to be considerably higher.

There are two major competitive Democratic House primaries: Rep. Rep. Lloyd Doggett in the new 35th district and Rep. Silvestre Reyes in the 16th district. Both are heavily Democratic districts.

“Where there are high profile Democratic primaries in the state, the voting base is pretty hard-core Democrat,” notes Democratic strategist Joe Householder, a fact, he added, that should add to Obama’s support.

* Texas has a significant minority population. There are 3.8 million eligible Hispanic voters in Texas, second only to California. A full quarter of the state’s eligible voters are Latino. That should provide Obama a boost that he did not get in largely white Appalachia.

* Texas has several major urban centers. Obama has performed poorly in rural areas; that should be offset somewhat in Texas by support in and around Austin, Houston, Dallas and San Antonio. (Check out the pockets of blue in Texas’ major cities on this map of the 2008 election results.)

All of the above suggests that the protest vote will be smaller in Texas than in previous contests in Arkansas, Kentucky and West Virginia. And former Massachusetts governor Mitt Romney could also face some protest vote on his own side — from supporters of Texas Rep. Ron Paul who is one of seven Romney alternatives on the Lone Star State ballot today.