An internal poll from the campaign of Lt. Gov. David Dewhurst shows he has a big lead in the contest for the GOP nomination to succeed retiring Sen. Kay Bailey Hutchison (R-Texas).

Fifty percent of respondents said they would vote for Dewhurst, which means he might be able to avoid a runoff.

He far outpaced his Republican rivals, but the battle for second place is becoming more heated. Former Dallas Mayor Tom Leppert polled at 9 percent, and former Texas Solicitor General Ted Cruz came in at 5 percent. Former ESPN analyst Craig James got 3 percent.

Cruz announced Tuesday that he raised $1.1 million in the third quarter, and the Tea Party Express endorsed Cruz on Wednesday.

“We were careful in our endorsement selection,” Tea Party Express Chairwoman Amy Kremer said in a written statement. “When all is considered, Ted Cruz’s knowledge of the Constitution and focus on limiting the size, cost, and intrusiveness of the federal government make him not only the strongest candidate in the race, but one of the strongest Tea Party candidates in the nation.”

The group has backed Nebraska Attorney General Jon Bruning and Indiana Treasurer Richard Mourdock in GOP Senate primaries. Kremer indicated that more endorsements are coming.