The politics of the moment has this way of inflicting a case of selective amnesia among politicians.

Take last night’s 12th — and possibly final — Republican Party presidential debate with Donald J. Trump, Rafael Edward Cruz, Marco Rubio and John Kasich as providing an example of that peculiar malady.

One of them (I can’t remember who) brought up President Reagan’s famous buddy-buddy relationship with House Speaker Tip O’Neill. The two men — one Republican, one Democrat — worked well together.

Sure they did. I honor them for that cooperation.

So did a couple of other well-known pols. Democratic President Bill Clinton and Republican House Speaker Newt Gingrich also managed to find common ground when the need arose. And it did, particularly as it regarded the need to balance the federal budget.

None of these current GOP candidates, though, mentions that political partnership.

We all know why that is the case, of course.

It’s because the president’s wife, Hillary Rodham Clinton, wants to ascend to the office her husband once occupied.

Why, we just can’t give Bill Clinton any props for doing what the current president and the current congressional leadership seem unable — or perhaps unwilling — to do.

I’m the first to acknowledge that the Clinton-Gingrich relationship never evolved into the personal public friendship that Reagan and O’Neill developed.

The Gipper and the Tipper would share some spirits once they were off the clock, setting politics aside; it’s been reported widely how they would swap stories between them and laugh at the foolishness of the day.

I don’t believe I’ve ever heard of similar moments of non-political fellowship involving Bill and Newtie.

However, they certainly did form a valuable political partnership during the time Gingrich was speaker. It’s understandable, I suppose, that the Republicans running for president would choose to ignore it.

I’ll just have to rely on Hillary Clinton to remind the rest of us how bipartisan cooperation can work.

She was there, too.