Trump tears into Kristol on Twitter

After Weekly Standard editor Bill Kristol on Sunday evening talked up “an impressive” third-party candidate soon entering the 2016 race, Donald TrumpDonald TrumpSouth Carolina Senate adds firing squad as alternative execution method Ex-Trump aide Pierson won't run for Dallas-area House seat House Oversight panel reissues subpoena for Trump's accounting firm MORE ripped into him on Twitter, calling the prominent conservative voice a “loser” and a “dummy.”

Kristol, one of Trump’s most vocal detractors, has been actively seeking a White House candidate to challenge the de facto GOP nominee from the right, and Sunday he indicated progress:

Trump fired back in a trio of tweets, calling for Republicans “to be smart & strong” and rally behind him in the general election.

Earlier this month, an article from the Breitbart website called Kristol a “Republican spoiler” and “renegade Jew” for his efforts to undermine Trump. Many conservatives believe a third-party bid would split the GOP and hand the race to Democratic front-runner Hillary ClintonHillary Diane Rodham ClintonClintons remember former adviser Vernon Jordan Biden praises Vernon Jordan: He 'knew the soul of America' The parts of H.R. 1 you haven't heard about MORE.