AUSTIN — Ken Paxton and James Talarico held competing rallies in San Antonio and Plano on Sunday, the eve of early voting in a Texas Senate race that polls show inside the margin of error and that has drawn more than half a billion dollars in advertising.

Early voting runs from Monday through Oct. 30, ahead of Election Day on Nov. 3. Republicans hold the Senate 53-47, and the Texas seat, held by John Cornyn until Paxton defeated him in this year's Republican primary, has become one of the most expensive contests in the country.

No Democrat has won a Senate race in Texas since 1988, or any statewide office since 1994.

Paxton, the state attorney general, told supporters in San Antonio that the choice was between his opponent's agenda and "the simple things of faith, family and freedom," and called Talarico the "most radical Democrat ever to run statewide in Texas," CNN reported.

Talarico, a state representative from Austin, opened his "Clear Eyes, Full Hearts" bus tour in Plano, where he described Paxton as corrupt and unfit for office, according to CNN. The tour's name is a nod to the television drama Friday Night Lights, and members of the show's cast appeared in a video endorsing him.

A CBS News/YouGov poll of likely voters conducted Oct. 8-16 put Talarico at 51 percent and Paxton at 49 percent, within its 3.5-point margin of error. A University of Texas/Texas Politics Project survey had Talarico ahead 50 percent to 47 percent, and the RealClearPolitics average of polls taken between Sept. 24 and Oct. 14 gave him a lead of 2.2 points, CBS News Texas reported.

Spending on the race has passed $500 million, including the primaries and future ad bookings, according to the tracking firm AdImpact, with Republicans accounting for more than $368 million and Democrats for $132 million.

Talarico's campaign said on Thursday that it raised $64 million in the third quarter, which it described as the largest third-quarter total by any Senate candidate, surpassing the $57 million Jaime Harrison raised in South Carolina in 2020. His total since entering the race stands at $134 million. Paxton reported $18 million for the quarter, double his second-quarter figure.

Much of the Republican money has come from outside the state. Elon Musk gave $158 million to the Senate Leadership Fund, which passed the same amount to Texas PAC, the largest contributor to Paxton's campaign, The Associated Press reported, citing federal filings. Musk gave a further $10 million to Lone Star Liberty PAC. On the Democratic side, LinkedIn co-founder Reid Hoffman has donated $11.5 million to a super PAC backing Talarico, according to The Texas Tribune.

Paxton began his "Come and Take It" tour on Saturday before about 200 people at Rockwall Municipal Airport, east of Dallas. "This race is about defending our country and this great state of Texas," he said, according to The Dallas Morning News. The 18-day itinerary includes more than 30 stops and ends at the Alamo on Nov. 2.

At an earlier stop in Austin, Paxton set his record as attorney general against Talarico's in the state House. "Everything I just laid out puts money in your pocket. His entire record takes it out," he said, according to Fox San Antonio. He urged the crowd to vote early "and then I want you to spend the next two weeks getting everybody out to the polls."

Talarico spent Saturday in San Antonio, where he blamed tariffs on imported tomatoes for rising restaurant costs. "Chips and salsa are sacred in Texas," he said at La Fonda on Main. He rejected Paxton's characterization of his tax positions, saying, "Yeah, those are all lies. I do not support an income tax."

Talarico's tour covers 20 cities, with stops in Denton and Fort Worth on Monday, and closes with a rally in Austin on Nov. 2. "Texans are tired of being divided into teams – red versus blue, left versus right, rural versus urban," he said when announcing it.

Paxton was impeached by the Texas House over corruption allegations and later acquitted. Parker Hevron, a political scientist at Texas Woman's University, told CBS News Texas that those controversies were "baked into the cake of this race" and had not cost Paxton in previous statewide elections. He said a Talarico victory would be "a come-to-Earth moment for the Republican Party in Texas."

National Republicans have committed heavily to the seat. President Donald Trump has made three trips to Texas in a month to campaign for Paxton, and Vice President JD Vance appeared in Tyler on Tuesday, telling Republicans, "He fights for you. Let's fight for him."

Trump has also turned on fellow Republicans. "If Ken Paxton loses, it will be because of WEAK and INEFFECTIVE Political Hacks like John Cornyn and Karl Rove," he wrote on Truth Social. CBS News Texas said Cornyn's office had not responded to a request for comment.

Talarico, who missed nine days of campaigning earlier this month with the flu, has cast the race as a David-and-Goliath contest. "You are my slingshot," he told a rally in San Marcos on Thursday, the AP reported.

Early voting runs through Oct. 30. Talarico is due in Denton and Fort Worth on Monday, while Paxton's tour continues through Allen, Fort Worth, Houston and El Paso before finishing at the Alamo the night before Election Day.