WASHINGTON -- In the category of credit where credit is due, Donald Trump has been exactly right in one important respect. He attacked the Republican establishment as low-energy, cowering weaklings. Now Republican leaders are lining up to surrender to him -- like low-energy, cowering weaklings. The capitulation has justified the accusation.

It would be impolite to name names. So I should not mention that former Texas Gov. Rick Perry, who now angles for Trump's vice presidential nod, once said: "He offers a barking carnival act that can be best described as Trumpism: a toxic mix of demagoguery, mean-spiritedness and nonsense that will lead the Republican Party to perdition if pursued. Let no one be mistaken -- Donald Trump's candidacy is a cancer on conservatism, and it must be clearly diagnosed, excised and discarded." I should resist the temptation to recall how Rep. Peter King of New York, who now (reluctantly) backs Trump, once asserted he is "not fit to be president, morally or intellectually."

Singling out individuals is unfair in so great a company. One by one, Republican senators have made their peace with a Trump nomination. Many in the House GOP leadership and caucus have urged Speaker Paul Ryan to get it over with and endorse the presumptive Republican nominee. It is humorous -- in a sad, bitter, tragic sort of way -- to see Republican leaders, and some conservative commentators, try to forget or minimize Trump's history of odious proposals and statements. The argument seems to be: "I say tomato. You say Mexican immigrants are rapists. What's the big difference?"

And all this has taken place without (apparently) securing any concessions or guarantees from Trump himself. He now knows that he can violate any Republican or conservative principle and still get a round of crisp salutes, even from his strongest opponents. This is the white flag of ideological surrender.

I understand the short-term political calculation. Better to have Trump, who is ideologically unpredictable, make Supreme Court nominations than Hillary Clinton, who is reliably liberal. Better to have Trump rather than Clinton make all those plum executive branch appointments. Besides, if Trump is a liar, Clinton is a worse one. If Trump is a misogynist, well, consider Clinton's husband.

This justification has a few flaws. The first is reductio ad Trumpism. If Clinton is the ultimate evil, would anyone be better than she is? How about Trump's ex-butler, who threatened President Obama on Facebook? How about Trump supporter Phil Robertson of "Duck Dynasty"? Of course not, a Republican would angrily respond. A prospective president needs to be morally and intellectually fit for the office. He or she can't be guilty of demagoguery or mean-spiritedness, or talk nonsense all the time.

But this is exactly the issue. Were Perry and King correct in their initial diagnosis of Trump? If so, we are not dealing with the normal give-and-take of policy and politics. We have left the realm of half a loaf and you scratch my back. We are dealing with a question of fitness for the highest office in the land. It is not enough for GOP partisans to assert Trump's superiority to Clinton on this issue or that. They must justify that Trump has the experience, knowledge, temperament, judgment and character to be president of the United States. That is a more difficult task.

This leads to a second objection. Pursuing the short-term interests of the GOP, gained by unity, may actually damage or destroy the party in the longer term by confirming a series of destructive stereotypes. Republicans stand accused of disdaining immigrants; their nominee proposes to round up and deport 11 million people. Republicans are accused of religious bigotry; their nominee proposes to stop all Muslims at the border. Republicans are accused of a war on women; the Republican nominee, if a recent New York Times expose is accurate, is the caveman candidate.

All this is a particular blow to conservatives, of which I count myself one. Conservatives latched on to the GOP as an instrument to express their ideals. Now loyalty to party is causing many to abandon their ideals. Conservatism is not misogyny. Conservatism is not nativism and protectionism. Conservatism is not religious bigotry and conspiracy theories. Conservatism is not anti-intellectual and anti-science. For the sake of partisanship -- for a mess of pottage -- some conservatives are surrendering their identity.

It is a very bad deal.

(c) 2016, Washington Post Writers Group