There are times when simple moral decency requires one to rise above politics.

When Donald Trump implied that all Mexicans immigrants were rapists, Republicans rationalized that Hillary Clinton was worse.

When Trump made misogynistic comments about women, Republicans soothed themselves with the possibility that he might make good Supreme Court appointments.

When he threatened to ban an entire religion from this country, Republicans talked about the failures of Barack Obama.

When Trump re-tweeted racist nonsense about black crime, Republicans talked about party unity.

As trump welcomed the Alt-Right and openly avowed racists and anti-Semites into the ranks of his campaign, Republicans endorsed him.

But Trump’s recent attacks on a federal judge for the offense of being “a Mexican” is as morally offensive as any action by a presidential candidate in modern history. Set aside the fact that Gonzalo Curiel, was born in Indiana, and is as American as you or me. Set aside the fact that Judge Curiel is a courageous man who was actually forced into hiding after taking on the Mexican drug cartels. Set aside, even, the impropriety of a presidential candidate trying to intimidate a judge in a case where he is a litigant.

Set aside all that. Trump’s attack on Judge Curiel is plain and simply racist. The idea that Americans are defined by the ancestry and that people of certain ethnicity cannot be trusted to do their jobs, is the very heart of racism. It is wrong. More than wrong, it is morally repugnant.

So to my Republican friends, I say this is no longer about whether Trump might be slightly better than Hillary on this issue or that one. We would not have said, “well, David Duke had great views on the Second Amendment,” “I like George Wallace’s tax policy,” or “The Klan has a point about quotas.”

This is now about conscience. To continue to support Donald Trump is to acquiesce in the darkest impulses of mankind and stains the American soul. It is not about politics, it is about right and wrong.

I have known Paul Ryan since he was a legislative staffer. I know he is a fundamentally good and decent man. But in continuing to support Trump, he diminishes himself. The same is true for all those other Republicans, from Marco Rubio to John McCain to Bob Corker, who have sold their moral credibility for the sake of party unity or some other temporary political gain. It must stop.

When, someday in the future, your children or grandchildren ask you where you stood today, how will you answer them?