Emmanuel Macron has hacked away at civil liberties, with heightened police repression and ministers promising to root out “Islamo-leftism.” Marine Le Pen would be much worse — she’ll wage all-out war on France’s democratic institutions. Spirits were low last Tuesday at the Dorothy, a café and community space in Paris named after Catholic American labor activist Dorothy Day. Two days earlier, Jean-Luc Mélenchon, leader of the left-wing France Insoumise, had finished third in the first round of France’s presidential election, a little over 400,000 votes shy of qualifying for the runoff. The reality was sinking in that on April 24,...