To be sure, Democrats have sometimes gone too far as well — by, for example, comparing the whole of the Tea Party to the Ku Klux Klan, as Representative Alan Grayson did last year. And even after having his comparison rebuked by the Democratic Congressional Campaign Committee chairman, Grayson dug in his heels, refusing to apologize, instead saying “sometimes the truth hurts.”

But there are two important differences here. First, the Democratic Party is not suffering a diversity crisis; the Republican Party is.

Second, the impression beginning to take hold is that the Republican Party is a home for the hateful, not necessarily because the party invites them, but because it doesn’t forcefully enough reject them.

How does this sit with minority members in the party’s ranks and those it hopes to attract? How can they be expected to find a home among such hostility? And why aren’t more party leaders willing to take a stand and stamp out the bigotry?

Minority voters who happen to be conservative are looking at these incidents, no doubt, and hearing the horror of supposed friends’ silence. As the Rev. Martin Luther King Jr. put it: “In the end, we will remember not the words of our enemies, but the silence of our friends.”

For better or worse, ours is a two-party system, and I fervently believe that a healthy, idea-oriented opposition helps keep everyone honest. If we disagree on the size and role of government, let’s have that debate. If we disagree on the role America should play in helping to police the world’s quarrels, let’s have that debate. If we disagree on the best way to jump start the economy, best prepare our children, fix our broken immigration system or adjust our system of taxation, let’s have all those debates. But when the debate devolves into invectives born of hate — racist, misogynistic, homophobic or otherwise — it ceases to be healthy or productive and instead dredges up the worst of who we were and, in some cases, remain.