If you want to know whether Donald Trump’s political stock is up or down within the Republican establishment, watch Nikki Haley.

She’s my favorite weathervane. Not a well calibrated weathervane, as we’re about to see. But if the slightest breeze is blowing against him among the institutional party, the Haley-o-meter will detect it and start to whirl.

She began as an adversary. In January 2016, with Trump leading GOP primary polls, Haley delivered the party’s rebuttal to the State of the Union with a shot at its anti-immigration presidential frontrunner. “During anxious times, it can be tempting to follow the siren call of the angriest voices,” she said. “We must resist that temptation. No one who is willing to work hard, abide by our laws, and love our traditions should ever feel unwelcome in this country.”

Ten months after warning about “the siren call” of his angry voice, Haley agreed to join Trump’s new administration. The weathervane had spun for the first time.