There is an interesting moment in J. Anthony Lukas’ Common Ground, his epic book on the bussing crisis in South Boston. Folks gather in a park, where graffiti reads: “Gays Suck. Liberals Suck. Brits Suck. N***ers Suck.”

There is only one ethnic group on the planet who could express such a diverse array of rage and hatred: Irish Catholic Americans.

This came to mind as yet another storm thundered out of Washington this week, smearing all involved -- President Donald Trump, White House Chief of Staff John Francis Kelly, MSNBC host Lawrence O’Donnell.

It all began…well, it’s hard to say.  Was it when Trump told another absurd lie and said no other presidents phoned the families of fallen soldiers?  Or when Trump told the wife of a fallen soldier that this particular hero “knew what he signed up for?”  

Or when the Democratic congresswoman who happened to be sitting with the war widow when Trump called decided to go public with the fact that the widow was upset by Trump’s remarks?

There are already boatloads of blame to go around here.

But wait!  There’s more!

Then Kelly -- an honorable man who has served his country, and whose sons served this country, one of whom paid the ultimate price -- lashed out and told a series of his own semi-truths about the African American congresswoman.

I mention Congresswoman Frederica Wilson’s racial background because Irish American MSNBC pundit O’Donnell opined that Kelly’s nasty words were, in part, motivated…by Kelly’s youth in heavily Irish South Boston!

“I know the neighborhood John Kelly comes from. I know the culture,” said O’Donnell. “You know what wasn’t sacred when he was a kid growing up, where he was growing up? Black women.”

MSNBC’s Joy Reid, on Twitter, dumped gallons of gasoline on this already-raging firestorm, adding, “Kelly grew up in segregated Boston…in an Irish Catholic neighborhood where women were bullied not honored and blacks scorned and rejected.”

Look, if you’ve got a problem with Trump or Kelly, say it loud and proud.  Lord knows there’s plenty of problems there.  But psychoanalyzing the ethnic geography of Kelly’s “culture” is not the way to go about it.  It actually gives pundit pinheads like Tucker Carlson something like the moral high ground.

To O’Donnell and Reid, Carlson said, “The problem isn’t just General Kelly. It is the Irish, they’re the problem. This is grotesque, obviously.”

But no less grotesque than Carlson himself.  

As part of this very same rant, Carlson dubbed Reid and O’Donnell “morons,” before going on to lament that Reid and O’Donnell are killing “traditional political debate” with -- wait for it -- their lack of civility!

On a deeper level, this is just the latest in a long line of Republican efforts to woo Irish Americans. Again and again, right wingers wink and nod to these wavering Democrats and say, “See, we’re the group you really belong to.  Not them.”

Of course, O’Donnell has made it awful easy for the likes of Carlson to do this, hasn’t he?

But Kelly deserves plenty of blame in all of this, too.  If he has served his country nobly, he has also chosen to align himself with a demagogue who seems to lie every time he breathes. Worse, Kelly himself seems to be taking to these shameful tactics.

It’s the same thing with Republican House speaker and Irish wonderboy Paul Ryan.  There’s much you can say about Ryan, but he’s no lying demagogue.  

But like Kelly -- unlike, say, John McCain -- Ryan gets dragged into the Trump muck and it gets harder and harder to emerge with any sense of decency.

This week, there was Ryan -- who touts his Catholic faith even as America’s bishops blast his own party on immigration and poverty -- yukking it up at the Al Smith dinner, poking fun at Trump.

Very soon, none of this is going to seem funny.