Texas AG Ken Paxton is running hard against four-term Senator John Cornyn in a nasty primary, framing it as a fight against an entrenched incumbent backed by big-money donors.

• Cornyn has out-raised Paxton 17 to 1, with most of it coming from DC donors and a $10.9M pack whose backers are hidden.
• Paxton says Cornyn has nothing to run on after 42 years in office and has sided with Democrats on guns, Afghan refugees, and the border wall.
• Trump has not endorsed yet, and some markets think he may sit it out given his past clashes with Cornyn over January 6 and Trump's legal cases.
• The winner faces Democrat James Talarico, who just got Obama campaigning with him and out-raised both Republicans in the first quarter.
• Paxton brushes off personal attacks about his marriage, saying he would rather lose than drag his kids and grandkids into it.

Outlook: The primary is decided in under two weeks, and Trump's endorsement, if it comes, will likely decide it.