Arizona Sen. Jeff Flake told CNN’s State of the Union that he is still not planning to vote for Trump and he worries that the Republican nominee could lose his state of Arizona, which Republicans haven’t lost in the presidential election since 1996.

The Arizona senator has been critical of Trump throughout the campaign, expressing concern for Trump’s treatment of a gold star family, his position on immigration and Trump’s lack of specificity regarding foreign policy.

“I would not vote for Hillary Clinton, and, as of now, I would still not vote for Donald Trump,” Flake told CNN, according to a report in Politico. “I just know that I would like to vote for Donald Trump. It’s not comfortable to not support your nominee. But, given the positions that he has taken and the tone and tenor of his campaign, I simply can’t.”

Throughout the campaign, Flake has been openly critical of Trump. During a meeting on Capitol Hill this summer, Trump even called Flake out specifically for his attacks against him.

Trump responded to Flake Sunday evening, tweeting that Arizona needed stronger senators.