When Donald Trump was declared the presumptive GOP nominee last week, longtime GOP operative and political analyst Bill Kristol starting actively courting third party candidates as voters on both sides of the political aisle expressed discontent with their choices.

Late last week, it was reported Kristol met with former Massachusetts Governor and 2012 GOP presidential nominee Mitt Romney about a third party run and during an interview Monday with CNN, Kristol said there's a 50/50 chance we'll see a viable candidate emerge.

"There's a 50/50 chance," Kristol said on CNN's At This Hour.

Kristol stressed during the interview that if a third-party candidate were to enter the race, it would need to be someone credible and with legitimacy in order to bring in voters.

Last week Nebraska Senator Ben Sasse posted a lengthy letter on his Facebook page exploring a third party option. He made the argument that the country deserves better than Hillary Clinton and Donald Trump.

RNC Chairman Reince Priebus is calling for unity behind Trump and is not open to a third party run.