Nearly $100 million spent on campaign advertising for Texas Senate seat, report says

In Fort Worth, Sen. John Cornyn made his case why voters should elect him to a fifth term in the U.S. Senate. 

"I think I'm a whole lot more effective now than I was when I first started,"  he said.

But the latest independent poll released last week by the University of Houston shows Cornyn is trailing Attorney General Ken Paxton 38% to 31%, with Houston Congressman Wesley Hunt at 17% and 12% remain undecided. 

The primary is widely expected to end in a runoff on May 26. The organization Ad Impact Politics reports $98.2 million has been spent and reserved on campaign advertising in both the Republican and Democratic primaries for the Senate race. Of that, nearly $59 million was spent by Cornyn and PACS and other groups supporting him. 

Cornyn defends high spending

CBS News Texas asked Cornyn about the spending and whether an incumbent should have to spend all that money to stay in office.

"Texas is a big state; it's hard to get your message out, and it takes money," Cornyn said. "I'm proud of the fact that there are so many people who've dug so deeply to support me. It's going to be a whole lot more expensive for Republicans to hold onto this seat if I'm not the nominee than if I am."

Paxton confident despite criticism from Cornyn, Hunt

In Allen Tuesday night, Paxton rejected concerns by Cornyn and other Republicans that if he is the party's nominee, they are at risk of losing the Senate seat to the Democrats. 

"I don't care who I face," Paxton said. "I've run these races. I've had statewide races three times. They always say the same thing. I've done very well in every race that I've been in." 

Hunt highlights $3 million spent on negative ads targeting him  

In Dallas on Monday, Hunt told CBS News Texas that both Paxton and Cornyn have felt the need to run a barrage of negative ads against him. 

"My two opponents have spent $3 million in the past few weeks in attacking me, so our message is clearly resonating with the people here in Texas," said Hunt. "That means, we are right over the target zone."

Spending expected to climb with possible runoff, general election campaign ahead  

Spending will continue to climb in the Senate race with the expected runoff election in the GOP primary. After that, there will still be five months of campaigning for the general election in November. 

Aside from money, Cornyn is hoping word of mouth will help. At the Fort Worth Police Association on Wednesday afternoon, various law enforcement associations from North Texas and around the state, including Fort Worth Congressman Craig Goldman and Mayor Mattie Parker, endorsed Cornyn. They praised his support for men and women in blue, and Parker said Cornyn is a man of his word. 

"Both as my time as mayor and before, when I had been working in Texas politics, the person you always chose to call was Sen. John Cornyn," the mayor said. "He was someone you respected, that would get into the trenches with you on tough issues, no matter what they were."

Cornyn urged his supporters to go to the polls and vote. Early voting continues through Friday, Feb. 27.

Watch Eye On Politics at 7:30 Sunday morning on CBS News Texas on air and streaming