In 1956, when Sen. John F. Kennedy published his Pulitzer Prize-winning book “Profiles in Courage,” he quoted a dour Walter Lippmann column. “With exceptions so rare that they are regarded as miracles and freaks of nature,” Lippmann had written, “successful democratic politicians are insecure and intimidated men. They advance politically only as they placate, appease, bribe, seduce, bamboozle, or otherwise manage to manipulate the demanding and threatening elements in their constituencies. The decisive consideration is not whether the proposition is good but whether it is popular — not whether it will work well and prove itself but whether the active talking constituents like it immediately.”

In his book, Kennedy took issue with Lippmann’s verdict, arguing, with reason, that “In no other occupation but politics is it expected that a man will sacrifice honors, prestige and his chosen career on a single issue.” And yet here Kennedy was, writing a book that did just that — testimony that those whom Lippmann called “miracles and freaks of nature” were in fact singular cases. To Kennedy, political courage — the act of voting at risk to one’s own electoral fate — was to be celebrated.

Always vanishingly rare, political courage is virtually extinct now. Over and over again, we are told the great fact of our politics in the Age of Trump is that our elected representatives fear crossing the aisle because they will pay a price at the polls — a courageous vote, in other words, will be rapidly followed by defeat and exile from office.

There’s a problem, however, with this prevailing piece of conventional wisdom: It’s wrong. Over the past six decades, courageous high-profile votes have tended not to cost the courageous their seats. From Southern Democrats who supported the Civil Acts Right of 1964 to Republicans who backed Medicare and Medicaid in 1965 through the Clinton impeachment in the 1990s, tough votes have been difficult but not necessarily fatal.