U.S. Sen. Mark Kirk (R-IL) says he "cannot and will not support" Donald Trump as his party's presidential nominee.
Kirk made that announcement Tuesday, as he denounced Trump's attacks against the ethnicity of a federal judge overseeing the Trump University fraud case.
"I have spent my life building bridges and tearing down barriers-not building walls. That's why I find Donald Trump's belief that an American-born judge of Mexican descent is incapable of fairly presiding over his case is not only dead wrong, it is un-American," Kirk said in a statement.
"As the Presidential campaign progressed, I was hoping the rhetoric would tone down and reflect a campaign that was inclusive, thoughtful and principled. While I oppose the Democratic nominee, Donald Trump's latest statements, in context with past attacks on Hispanics, women and the disabled like me, make it certain that I cannot and will not support my party's nominee for President regardless of the political impact on my candidacy or the Republican Party.
"It is absolutely essential that we are guided by a commander-in-chief with a responsible and proper temperament, discretion and judgment. Our President must be fit to command the most powerful military the world has ever seen, including an arsenal of thousands of nuclear weapons. After much consideration, I have concluded that Donald Trump has not demonstrated the temperament necessary to assume the greatest office in the world."
Kirk -- who previously said he would support Trump if the businessman became the GOP nominee -- is locked in a tough re-election fight against challenger U.S. Rep. Tammy Duckworth (D-IL,8).
Duckworth and her campaign have hammered Kirk over his silence on Trump's attacks.
In response to Kirk's announcement today, Duckworth deputy campaign manager Matt McGrath released a statement:
What took so long? Apparently for Mark Kirk, it's acceptable to refer to Mexicans as rapists; to propose banning Muslims from entering the country; to call women fat pigs and dogs; to mock a reporter's disability; and to insult just about everyone who doesn't look like Donald Trump. Until today, and for nearly a year, Kirk was fine with all of that, and even saw a 'net benefit' in Trump's campaign, and offered himself up as a potential adviser. Yesterday, Tammy Duckworth called Senator Kirk's silence in the face of Trump's bigotry a betrayal, and we're standing by our statement.