Scoop: Paxton PAC goes up with first negative ad against Cornyn

• In May, Cornyn was down by double digits in some polls. But he has narrowed the gap this summer, drawing to within single digits in most surveys.
• But his movement hasn't come cheap, with Cornyn-allied super PACs having spent or reserved roughly $14 million in the last two and a half months, according to AdImpact.

Driving the news: The new digital ad from the Lone Star Liberty PAC, which is supporting Paxton, uses old anti-Cornyn quotes from Trump and suggests that the senator isn't a true conservative.

• "Cornyn trampled on our conservative values and Second Amendment rights," the narrator says.
• The Lone Star PAC raised $1.86 million in the second quarter, according to FEC filings.
• The Texans for a Conservative Majority PAC, which is aligned with Cornyn and counts Chris LaCivita as an adviser, raised $10.9 million last quarter, according to the FEC.
• Across all committees, Cornyn has a massive cash advantage.

Between the lines: Most of the ads Cornyn's super PACs have been running have driven positive messages for the senator.

• But the Cornyn team went up with negative ads around Labor Day, calling Paxton's ethics into question.

• Republicans in Washington are concerned the primary will be nasty and brutish and will leave the winner wounded for the general election, potentially imperiling what should be a safe GOP seat in deep-red Texas.

By the numbers: An August survey from Texas Southern University found Paxton holding a five-percentage-point lead over Cornyn among likely primary voters. But that was down from a nine-point lead from the same survey in May.

• And an Emerson poll in mid-August had Cornyn up one percentage point, with 30% of Texas GOP primary voters, and Paxton with 29%. The margin of error was +/- 4.4%.