Every Republican senator needs to know some key, invariable facts:

The moment they vote to deny witnesses, they seal their own political fate.

The blow won’t just come from the Democrats or from outside groups.

It will come from Trump himself. Because the moment you deny witnesses, Trump will know his exoneration is inevitable.

And he will start bragging about it.

He will start talking about it. He will tweet about it.

And then as the evidence emerges in dribs and drabs, and as the facts you covered up become public, you own them.

You’re on the whole story.

He’ll laugh and let you all burn to the ground.

He’ll let you take the political damage, absorb all the radiation, and to lose more seats.

More importantly, like any criminal who forces someone to become an accomplice, he’ll know that you’re morally weak and mentally unable to ever resist him.

He’s an abuser, the Ike Turner of presidents, and no matter how many times you beg he still going to knock you around.

Finally, a favorite trope in advertising is — rightly — the “X cast the deciding vote.”

Y’all are looking at 3 votes for witnesses, tops.

You’re the deciding vote.