It's time for Republican leaders to do more than simply shake their heads and cluck their tongues over Donald Trump's bigoted attacks on a federal judge because of his ethnic heritage.

Speaker Paul Ryan (R-Wisconsin) today said Trump's behavior is "the textbook definition of racist comments" and should be "absolutely disavowed."

He's right.  So what's he going to do about it?

Other leaders have made similar statements, but Trump responded by doubling down in his attacks on the judge.

It's time for Ryan, Newt Gingrich, Mitch McConnell, Bob Corker and the rest (see Political Insider) to stop talking and start acting if they want Trump to clean up his act.

They can't justify their condoning Trump's racism by saying, as these men have, that Hillary Clinton "would be worse" than electing a dangerous, erratic, misogynistic, bigoted, lying, hate-monger.  Whatever her flaws, they pale in comparison; she would be an infinitely better president.

GOP leaders must reexamine their embrace of Trump; they are either on board with what he is saying or they must withdraw their endorsements.

In doing so they have a chance to rescue their own dignity and possibly prevent Trump from taking down many of their colleagues on Capitol Hill and in other down-ballot races across the country. 

Washington Post columnist Richard Cohen called the Speaker's failure to act a "profile in cowardice."  Ryan can't just bemoan Trump's bigotry.  It is time, in the words of former president Herbert Hoover, for "a summons to integrity and courage."