I don't do shots.

No matter who's trying to get me to pour tequila or whiskey or — ugh — Fireball down my throat, I say no. Always. It's a policy, and I hold firm to it.

The reason is simple: Nobody has ever woken up in the morning and said, "I wish I did more shots last night."

Sometimes in life, it's important not to overthink things. Just set a rule that's likely to preserve your dignity and follow it.

In the case of Republicans deciding whether or not to endorse Donald Trump, they should be following a similarly simple rule.

They should ask themselves, "If I do this, will I feel ridiculous in a year?" If the answer is yes, then don't do it.

Do not listen to those who would try to convince you to do a ridiculous thing in the name of party loyalty or personal self-interest. If your future self is going to feel ridiculous and undignified, what good is career advancement, anyway?

This advice applies to all Republicans, but it's especially aimed at House Speaker Paul Ryan, who is clearly weighing whether his own standards of personal dignity will allow him to endorse his party's candidate for president.

On Wednesday, Ryan again said that he's "not ready" to back Trump — who, incidentally, has spent the first part of this week reopening the conversation over former Clinton White House aide Vince Foster's death.

There is an obvious and facile case that it is in Ryan's self-interest to board the Trump Train. Not endorsing his own party's nominee is going to get only more awkward over time. By endorsing Trump, Ryan would avoid charges of disloyalty and protect his speakership.

But what about Paul Ryan's dignity?

When he looks back on this campaign a year from now, how would he feel about a choice to spend six months telling Americans that it is a good idea to make Donald Trump their president? Would that feel like it was a dignified choice, one that he can discuss proudly with his children?

Could future Ryan convincingly argue that supporting Trump served the causes Ryan purports to care about — such as shrinking the entitlement state (which Trump says he opposes) and making Republican rhetoric nicer (of which Trump does the opposite)?

Chris Christie and Donald Trump. REUTERS/Scott Audette

As Ryan considers how best to preserve his dignity from the threat of Trump, it's important to remember that while Trump has outwitted and beaten a lot of people through the course of this campaign, he has stripped only the dignity from people who surrendered it willingly — plus Jeb Bush:

When Ryan looks at these examples of people who have bent to the will of Trump, does he envy them? Does he wish that he was more like Christie right now?

Ryan cannot do anything about the fact that Trump has ruined his plan to work with a Republican president to dramatically reshape how the government taxes and spends. Ryan's grand plans for 2017 are in ruins, whether he endorses Trump or not, and whether Trump wins or loses.

That means the only thing of value Ryan has left is his dignity — and it would be quite irrational for him to allow it to be taken from him.