If you are an elected Republican officeholder, think long and hard before jumping on the Donald Trump bandwagon.

It's a presidential election year. Naturally you're thinking of your political career. That's a given. You have principles, but you also measure the political winds. You care about your position within the Republican Party. You watch who is rising and who is falling.

You might not admit it in public, but at times you imagine yourself as a future cabinet secretary or vice president, or even as a president someday.

Thinking about those long term goals, you realize that reaching them is not simply about judging who is winning right now. It's about your character and judgment in knowing when a front runner is radioactive and could poison your career.

Donald Trump is not just another Republican candidate. His clear pandering to racist voters, his over-the-top sexism, his unapologetic vulgarity, and, perhaps more than anything else, his cynical lack of principle and substance now threaten to become defining features of the Republican Party.

It is therefore partly up to you to decide how bad the damage will be, and how much it will afflict you personally.

Trump's nomination is likely to cost the party more than just the Senate, some governorships and some state legislatures. It could set the Republican Party back years, perhaps decades. Trump is almost precisely what Democrats have long and slanderously depicted Republicans to be — an insouciant and rapacious billionaire bully, who cuts ethical corners to enrich himself without regard to the little people. His elevation to the presidential nominee would repudiate the Reagan Revolution that turned the GOP into a majority coalition 36 years ago. The party he leads would not be conservative.

The toxicity of Trump would taint everyone who got near. Young voters, who already lean Democratic, would shun the Party of Lincoln. It could lose them for a generation. A party that was great in its origins and has been great in its achievements has every reason to be great in the future, too. But only if it chooses principled leadership. A huckster will not do.

And then there are Hispanic voters, who in Texas at least have shown genuine interest and willingness to vote for GOP candidates. That too may not last.

In coming days, you will consider what will be best for your own future. And yes, you will think about endorsing Trump, as New Jersey Gov. Chris Christie did recently. Who knows, you might be offered something nice.

But if you decide to fall into line and take your marching orders from Trump, you will lose respect (not least, your self-respect) and alienate millions of conservative Republicans. Look at Gov. Chris Christie, whose endorsement has transformed him from the tough-minded straight-talker, admired and widely regarded as a plausible national leader, and made him instead a forlorn and obsequious footman waiting in the front-runner's shadow to do his bidding.

You will put your career at risk. And if Trump loses to Hillary Clinton, whether in a landslide, as current polls suggest, or at all, it will all have been for nothing.

Half a dozen newspapers in New Jersey have now called on Christie to resign in disgrace. In his appearances with Trump, he looks like a man with no remaining dignity, like a prisoner giving a false confession in a North Korean propaganda film. He is now being brutally mocked, not only by conservatives, but in mainstream publications as well.

That man could be you. But not if you refrain from causing your own political demise.

Can you really back a man who, when asked to disavow the Ku Klux Klan, responded with hesitant political calculation rather than clear principle? Why would people ever trust your judgment again?

The weak-kneed politicians in the establishment will be watching your example. Some of them, like Christie, are willing to serve a new master because they think they will get something in return. Christie won't, and you wouldn't either.