An anti-Trump bolt will appeal to ideological conservatives, to libertarian leaners, and to the most religiously observant Republicans: what Republican strategist Grover Norquist has called the “leave us alone coalition.” What happens if that coalition does not run strongly in 2016? If it picks up something more like John Anderson’s 1980 6.6 percent of the vote, rather than Ross Perot’s nearly 20 percent? John Anderson ran as a liberal Republican who could not accept Ronald Reagan’s leadership—a group we have not heard much from since 1980. That’s the risk of political tests of strength: Sometimes you lose, and afterward nobody fears you ever again.

A “true conservative” independent race for president may offer anti-Trump Republicans a way to vote their consciences without endorsing Hillary Clinton. But it may also expose “true conservatism” as a smaller factor in U.S. presidential politics than it’s been regarded as since the advent of the Tea Party. And it will leave the instrumentalities of the GOP in the hands of people who were willing to work with Trump, and whose interest post-Trump-defeat will be in adapting his legacy to the future rather than jettisoning it.

Which is not to argue against it. Sometimes a political movement must and should go down fighting. Many conservatives will feel that way about opposing Trump in November 2016. The alternative—ticket-splitting between Hillary Clinton at the top and Republicans down-ballot—also carries daunting dangers. But whatever is decided by conservatives who refuse to board the Trump train, that decision is best made without illusions and false hopes. This election closes a long period in American politics. Whatever comes next, that period will not return.