President Donald Trump is withholding his endorsement in the Texas Republican Senate primary. Observers say the move is intended to press Republican senators to support the Safeguard American Voter Eligibility (SAVE) Act, legislation supporters say would strengthen election security and clarify voter eligibility standards.

“Trump has remained very steadfast that he wants this done, and that is a huge priority, and he’s getting pissed off at these members and at [Senate Majority Leader John] Thune,” a Republican operative, speaking anonymously, told Politico. (RELATED: Longtime GOP Senator Lives To Fight Another Day, But Foe Will Have One More Shot To Oust Him)