The chairman of Ted Cruz’s campaign in Kansas says the Texas senator has “harmed himself immeasurably” by not endorsing Donald Trump as the Republican presidential nominee.

Kansas state Rep. Mark Kahrs of Wichita said Thursday that he is disappointed in Cruz’s failing to endorse Trump.

Kansas Gov. Sam Brownback also said he was disappointed. Brownback said that at bottom, Cruz made a pledge to support the eventual nominee.

Kahrs said during a telephone interview from the Republican National Convention in Cleveland that the GOP must focus on defeating presumed Democratic nominee Hillary Clinton.

But Brownback said he’s not sure how much Cruz damaged his political future.

The governor was also in Cleveland. He endorsed Florida Sen. Marco Rubio before the state’s March presidential caucuses. Cruz won handily.