If they want to learn something about integrity, Paul Ryan and Mitch McConnell need to come to New Jersey.

Gov. Christie is invited as well, if Donald Trump's Travelling Hypocrisy Bandwagon grants him hiatus.

Here's the lesson: You can't support something anathema to your ideals, just like you can't put party loyalty ahead of principle or political gain above human decency.

Not if you still value your credibility, anyway.

This lesson comes courtesy of Hackensack Mayor John Labrosse, who decided that his affiliation with the Republican Party cannot hold up against Trump's vile remarks about the kind of people who live in his Bergen County city.

Labrosse and his Deputy Mayor, Kathleen Canestrino, issued a statement Thursday that called attention to Trump's relentless bigotry, which they assailed as "insulting to many of our people and completely unacceptable. We don't want a young student in one of our schools hearing these things and believing that their own elected officials are supporting these types of statements."

And then they put the GOP in their rear-view mirror - literally schlepping to the county Board of Elections to quit the party by changing their affiliation to independent.

Sure, there's no way of knowing whether Labrosse would take the same action if he ran, say, Upper Saddle River. But racism should be a deal-breaker, a party-ender, for anyone in 21st century politics. You don't have to be a mayor of a city where nearly 40 percent of the people are foreign-born, and where one-third speak Spanish at home.

As Labrosse said from his office Friday, "I believe all municipalities should be nonpartisan. It galvanizes government instead of dividing it. When you become what I call an established politician, you no longer are a servant of the people. You now serve an outside entity."

Let's contrast that with someone like McConnell, the second most powerful Republican in the land, who says that Trump is a hopeless ignoramus but is supporting him anyway.

"It's pretty obvious he doesn't know a lot about the issues," the Senate Majority Leader told Bloomberg Politics Thursday. "You see that in the debates in which he's participated."

But (always the but) this doesn't matter to McConnell, as long as there is an "R" attached to the candidate's name.

"For all of his obvious shortcomings, Donald Trump is certainly a different direction, and I think if he is in the White House he'll have to respond to the right-of-center world which elected him, and the things that we believe in," McConnell explained. "So I'm comfortable supporting him."

Just as mind-blowing was Ryan's verbal gymnastics pertaining to Trump, whom he embraced last week even though the candidate has campaigned against immigration reform, balancing the budget, open trade, and controlling entitlements - four tenets to Ryan's political life.

Then Trump made his remarks about Gonzalo Curiel, and Speaker Ryan could no longer hold back: The claim that a Mexican-American judge couldn't be impartial by virtue of his ethnicity was a "textbook definition of a racist comment," Ryan said.

But did Ryan withdraw his support? It is to laugh.

Apparently, one can abhor racist comments while clinging to a racist.

Christie, who once fought for the honor of a Muslim judge and won 51 percent of the Latino vote in 2013, is the new expert in this dichotomy.

These may not qualify as the worst Trump-related hypocrisies from party leaders, but if they want learn how to dislodge themselves from beneath these steaming piles of rationalization, they should come to Hackensack.

More: Recent Star-Ledger editorials.

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