Presidential hopeful John McCain may be the only Republican candidate close enough to clinch the party's nomination, but it isn't stopping supporters of Mike Huckabee from starting a grassroots effort to help Huckabee win Texas.

"Texas has the Republican party battleground," Huckabee supporter Rick Green said.

Texans for Huckabee, a new volunteer-driven group, announced its statewide efforts in press conferences in four of Texas' major cities.

It came on the heels of an endorsement of McCain by former President George H.W. Bush.

"He has the right values and experience to guide our nation forward at this historic moment," Bush said.

McCain, who spoke after Bush, said the endorsement would help the party move forward.

"I believe his endorsement and sign of support honors me, and I also think it's very helpful in continuing our effort to unite our party," McCain said.

But the party is not completely united, at least not yet. Huckabee supporters in Austin were critical of the party's "establishment elite" for wanting them to coalesce around McCain before Texas goes to the polls March 4.

"In Texas we don't cut and run, in Texas we don't give up and go home before the fight is over," Green said.

While Huckabee supporters concede it's a "long shot" for Huckabee to actually clinch the party's nomination, they said they want to send a strong message to "establishment" Republicans that the race is not yet over.

"It will help turnout," Texas GOP spokesman Hans Klingler said of the new grassroots organization. "And I guarantee you that at the end of the day Republicans will come back behind the nominee and will be ready for battle in November."