Dan Rather fired off a warning for those who say they disagree with Republican presidential candidate Donald Trump’s rhetoric but still support him: “History is watching.”

Rather, who was anchor of the “CBS Evening News” from 1981 to 2005, took to Facebook on Tuesday after Trump said “Second Amendment people” could deal with Hillary Clinton and the judges she appoints if elected ― comments many interpreted as a call to have her shot and killed.

“By any objective analysis, this is a new low and unprecedented in the history of American presidential politics,” Rather wrote. “This is no longer about policy, civility, decency or even temperament. This is a direct threat of violence against a political rival.”

Trump not only went against the norms of politics, he may have even broken the law.

“If any other citizen had said this about a presidential candidate, would the Secret Service be investigating?” wrote Rather.

“To anyone who still pretends this is a normal election of Republican against Democrat, history is watching,” he wrote. “And I suspect its verdict will be harsh. Many have tried to do a side-shuffle and issue statements saying they strongly disagree with his rhetoric but still support the candidate. That is becoming woefully insufficient. The rhetoric is the candidate.”

Read his full post from Facebook below.