The new president derides almost everything you claim to defend. You say you are for limited government and the rule of law over men; he denies all limitations. You say you are patriots; he praises a foreign kleptocrat while abusing his domestic critics and public servants. You speak of an independent free market; he intervenes daily with threats and blandishments. You remind us of the importance of norms and moral constraints, grounded in traditions. He seeks public attention by violating interpersonal, institutional, even sexual norms. You honor faith; he demonstrates ignorance of his own religion and contempt for others. You stand for cultural excellence and depth–he is a shallow vulgarian.

It will be tempting, nevertheless, to embrace this man because he aligns with you on certain matters that you are entitled to hold dear: taxes, Supreme Court nominations. Besides, liberals and progressives with whom you have a long and bitter feud hate him, and that inclines you to sympathy. His critics sometimes go beyond principled judgment to demonstrate bias against him. That makes you want to take his side. Your fellow travelers who have never struggled to understand or honor the hard principles of your movement–opportunistic politicians and performers who don’t know Hamilton from Madison or Burke from Hayek–are already jumping aboard. They have cast their lots and sold themselves that they might drink.

Liberalism will be fine. Liberals will lose favored policies, and as a result people will suffer, even die. But as a movement, liberalism will emerge unscathed, indeed, more unified, determined, and popular. It is conservatism that it’s at risk. And that is a problem for the country, which needs a conservative counterweight.

If you don’t stand explicitly against him, he will define what you stand for. Conservatism will mean Trumpism for generations to come. If you are very lucky, his administration will perform well enough that you will survive to continue your battle with the left and center-left. But if he leads the nation into a crisis or ruin, you will own that, too. And deservedly, because his mistakes will flow from his arrogant abuse of state power, which you, as champions of limited government, should have blocked.

“For the day of the Lord is near in the valley of decision” (Joel 3:14). Even in a century or more, it will be remembered where you chose to stand. Blow ye the trumpet, sound the alarm.