Donald Trump Threatens Third-Party Candidacy

Donald J. Trump has been roiling Republicans by attacking his rivals on their weak poll numbers and questioning their energy (Jeb Bush) and intelligence (Rick Perry).

But the larger threat that he poses to the party is the prospect that he could opt out and run as a third-party candidate. True to form, Mr. Trump is keeping the option open.

In an interview with The Hill newspaper published on Thursday, Mr. Trump said that many of his supporters have been urging him to consider a third-party run if he fails to secure the Republican nomination. Noting that the Republican Nationa