Voters in Texas are gearing up for what could be the biggest showdown yet between Democratic presidential candidates Hillary Clinton and Barack Obama. As VOA's Greg Flakus reports from Houston, much could depend on the state's somewhat complicated dual primary and caucus process.

It is becoming known here as the Texas Two-Step, after a popular dance in country music halls. In the Democratic primary, voters first choose a candidate through the normal voting process, then they use the proof of their having voted to enter a caucus in the evening. About two-thirds of the state's delegates to the Democratic party convention are chosen in the primary and a third from each congressional district come from the caucus results.

Complicating things further, the Clinton campaign has asked that no preliminary results from the caucuses be announced. Determining the full, official count could take some time, probably delaying a full count at least a day. But the important result for the public and for the candidates in terms of who has the momentum, will come not from the actual tally of delegates won, but from the overall victory in the popular vote statewide.

Analysts say even a narrow win here in Texas may not be enough for Clinton. In order to maintain her drive for the nomination, they say she needs big wins in both Texas and the other big state voting Tuesday, Ohio. The latest polls show her still well ahead in Ohio, but she is behind Obama by a few percentage points here in Texas. With the race that tight, however, a surge for Clinton on Tuesday could put her over the top as it did in New Hampshire in January, when polls showed her behind and she gained a surprise victory.

In her stump speeches, Clinton has been appealing to working class voters, Hispanics and women, putting special emphasis on the economy and what she describes as unfair trade deals such as the North American Free Trade Agreement, or NAFTA.

"I think we have to renegotiate NAFTA and what I am going to do is make it very clear; we need core labor and environmental standards, we need to end the provision that lets foreign companies sue to overturn protection for the environment and our workers," she said.

The attack on NAFTA has no appeal to business leaders here in Texas who say the trade agreement has been a resounding success for all three nations-the United States, Canada and Mexico. Cross-border trade on the Texas border with Mexico is booming. Critics also note that Clinton spoke in favor of NAFTA when her husband, Bill Clinton, was president. But many workers believe the agreement has been unfair to them and Clinton says it must be changed.

Clinton is also seeking an edge with voters by citing her experience in other foreign policy areas and by attacking her opponent, Obama, for his lack of experience.

Obama, however, has wasted no time in firing back.

"She has, supposedly, all this vast foreign policy experience," he said. "I have to say that when it came to making the most important foreign policy decision of our generation, the decision to invade Iraq, Senator Clinton got it wrong."

Obama says he opposed the war in Iraq from the beginning, while Clinton and the likely Republican nominee, Senator John McCain, voted for the authorization that gave President Bush the authority to invade Iraq. The war has had a big impact in this state, which hosts two large army bases as well as the hospital where many wounded soldiers are treated. Obama's message appears to have taken hold among blacks and younger voters and he is also drawing support from many independents and even some Republicans.