How panicked should we be about the rise of Donald Trump? A professor at Harvard, Danielle Allen, recently published a widely shared op-ed piece in the Washington Post likening his rise to that of Hitler in Germany.

Shes hardly the only one drawing that analogy. I did so myself back in September of 2015. Certainly, the last thing one wants to do is repeat the error of those who ignored or minimized the threat of Hitler until it was too late.

Im not telling anyone not to panic. But myself, I am just taking a deep breath or two and relaxing. I will probably get called a Trump enabler, or worse, for saying so. Alas, telling people to calm down doesnt generate the clicks or television ratings that the Trump panic does. But here  to help you sleep better, if nothing else  is a case that the alarm over Trump is probably overstated.

First of all, such Hitler hype has happened before, and been unwarranted. Steven Hayward, author of The Age of Reagan, recalls the rhetoric:

Democratic Rep. William Clay of Missouri charged that Reagan was trying to replace the Bill of Rights with fascist precepts lifted verbatim from Mein Kampf. The Los Angeles Times cartoonist Paul Conrad drew a panel depicting Reagan plotting a fascist putsch in a darkened Munich beer hall. Harry Stein (later a conservative convert) wrote in Esquire that the voters who supported Reagan were like the good Germans in Hitlers Germany....John Roth, a Holocaust scholar at Claremont College, wrote: I could not help remembering how 40 years ago economic turmoil had conspired with Nazi nationalism and militarismall intensified by Germanys defeat in World War I​to send the world reeling into catastrophe. . . . It is not entirely mistaken to contemplate our postelection state with fear and trembling.

Second, Mr. Trump hasnt even won the presidency yet. Theres a reasonable chance that Hillary Clinton would defeat him in a general election, vanquishing Trumpism for a generation to come and sending the Republican Party a clear message that if it wants to win the White House it will have to jettison the anti-immigrant platform.

Third, some of the shrillest alarms one is hearing about Mr. Trump come from conservatives who complain he isnt conservative enough. Erick Erickson writes, He defends Planned Parenthood, says he can cut deals in Washington, and believes in a socialist government run healthcare scheme.

The editorial in the famous anti-Trump issue of National Review faulted Mr. Trump for being too pro-immigrant: Trump says he will put a big door in his beautiful wall, an implicit endorsement of the dismayingly conventional view that current levels of legal immigration are fine. The magazine assailed his immigration policy as a poorly disguised amnesty.

Mr. Trumps ability to generate panic in both pro-immigrant and anti-immigrant precincts, among pro-life and pro-choice voters, suggests that at least part of the opposition to him is rooted not in policy differences but in aesthetics. Mr. Trumps opposition to the North American Free Trade Agreement and the Trans-Pacific Partnership trade deal, for example, is seen as intolerable nativism. But when Hillary Clinton takes the same position, people shrug it off as election-season pandering to labor.

The prospect that Mr. Trump would govern more soberly than he campaigns is another argument in favor of calming down. Confronted with a Democratic Senate or one with only a slim, non-filibuster-proof Republican majority and with a House of Representatives led by the big-hearted Speaker Paul Ryan, a President Trump would have to adjust to Washington reality.

Recent history, after all, has shown little connection between campaigns and governance. Bill Clinton campaigned on middle class tax cuts and gave us tax increases. George W. Bush campaigned on humility in foreign policy and gave us the Iraq War. Barack Obama campaigned against the individual mandate of Hillary Clintons health insurance plan, but ObamaCare wound up including precisely such a mandate. Mr. Obama campaigned as a uniter but wound up as a divisive president. Listen to Mr. Trump, and hes pretty open about some of his more extreme positions being opening offers for deal-making negotiations.

I dont expect to be voting for Mr. Trump. But I am not losing sleep over him, either.