When it comes to Lone Star State politics, Austin is the liberal hole in the conservative donut. So to speak.

It’s not shocking, then, that decidedly Democratic city has been abuzz over the news that Sens. Hillary Clinton and Barack Obama would hold a debate on the campus of the University of Texas on February 21.

That enthusiasm, however, quickly turned to disappointment after debate organizers announced the event would be closed to the public.

It’s not for lack of interest - more than 20,000 Texas voters had signed up for the Texas Democratic Party’s free drawing for a mere 100 tickets to the debate tickets, according to the Austin American-Statesman.

No reasonable explanation for the closed debate was given, but the nation’s eyes are still focused on Texas, which looms large in the Democratic race.

While Ohio also holds its key primary March 4, the Texas primary is drawing our attention because it’s bigger - 228 delegates - and in many ways, more compelling, with the various factors that could come into play.

The allocation of delegates - not statewide, but in each of the 31 state senatorial districts, which are not created equal - could play to Barack Obama’s advantage, according to the Houston Chronicle.

Largely because of their high turnout in the past, the Lone Star State’s two heavily African-American districts are expected to be a big factor.

Empirically, these areas may very well be granted at least 50 percent more delegates than the average senatorial district in Texas.

Therefore, it’s possible Hillary Clinton could top Barack Obama by 8-10 percent of the popular vote and split Texas delegates down the middle.

In a recent poll of likely Democratic voters in the Texas primary, conducted by Hamilton Campaigns, her edge is just that - 49-41 percent.

Her margins in other critical states, at least for now, are larger, leading some strategists to believe Texas provides Obama the best chance at an upset.

Texas appears more problematic for Clinton than Ohio or Pennsylvania (or even Wisconsin, voting Feb. 19), U.S. News & World Report believes.

This is due in part to Obama’s organizational edge and the fact that many independent white voters may vote in the Republican primary.

There’s also a good chance that younger voters, long marginalized in this GOP hotbed, will come out in force for Obama.