France's 2 left-wing presidential candidates refuse to unite

The two main left-leaning candidates in France's presidential election won't join forces after all.

Socialist Benoit Hamon and far-left candidate Jean-Luc Melenchon, a former member of the Socialist Party who is supported by the Communists, both announced over the weekend that they are staying in the race, putting the Left at risk of disappearing after the first round of balloting.

In France's two-round presidential election, voters will be choosing among a host of candidates on April 23 — and the top two vote-getters go on to compete in a presidential runoff on May 7. The exact number of presidential candidates will be set by the end of March.

Despite opinion polls...