AUSTIN -- State lawmaker Rick Noriega, D-Houston, officially announced Monday he's stepping forward to run for U.S. Senator John Cornyn's post.

It's a seat Democrats consider vulnerable because of Cornyn's loyalty to President Bush and presidential advisor Karl Rove. But the sitting junior senator says he's not thinking about next year's race yet.

"The Democrats are going to have their primary in March of 08, they're gonna choose their candidate, and I'm happy to let them campaign as I do the work of the people of Texas in the United States senate," Cornyn said.

Noriega follows fellow Democrat Mikal Watts in forming an exploratory committee.

Watts has donated $3.8 million of his own money to the race for the Democratic nomination, and committed to spend $6.1 of his own dollars on the general election. Watts also reported that he raised $1.1 million in the month of June.

For his part, Noriega said he believes Texans will "step up" and respond to a "call of duty" to support his campaign. Noriega is touting his competence -- Houston Mayor Bill White tapped Noriega to run the Houston convention center that took in and temporarily housed tens of thousands of Hurricane Katrina evacuees. He also served as a lieutenant colonel in Afghanistan, and says Iraq policy must change.

"Stubborness is not a foreign policy. When we have generals and other leaders of this nation feeding information and best practices and guidance and it isn't listened to, then we all suffer as Texans and as Americans," Noriega said.

Meanwhile, Republian U.S. Senator John Cornyn Monday launched the Texas Victory political action committee aimed at helping the GOP in 2008 elections.

Cornyn is seeking a second six-year term. Cornyn said Monday there's going to be a Democratic primary in March and they're going to choose their candidate.

Cornyn says he's happy to let them campaign while he does the work of the people of Texas in the U.S. Senate.

Cornyn raised $2.1 million for his campaign in the three months that ended June 30.

He finished the second quarter with $5.4 million in the bank.