The Virginia and North Carolina parties are in discussions about implementing a new requirement for candidates to qualify for their primary ballots: that they pledge to support the Republican presidential nominee — and not run as a third-party candidate — in the general election.

The procedural moves are clearly aimed at Trump, who pointedly refused to rule out a third-party run during the first GOP debate.

They come amid Republican fears that the real estate mogul is gaining strength in the primary contest, and that his jeremiads against undocumented immigrants will alienate Hispanic voters. Despite coming under a hail of criticism in recent weeks, Trump has held steady atop state and national polls.