George Stephanopoulos asked Hillary Clinton to explain why Donald Trump is doing so well

Hillary Clinton says Donald Trump's strong standing in the Republican primary race can likely be boiled down to his time in the national spotlight.

When asked by ABC's George Stephanopoulos on Sunday about Trump's status as the Republican front-runner, Clinton said Trump's appeal was rooted in his long stint as a reality-television star.

"I don't know, because he's a reality-TV star," Clinton said. "I mean, tens of millions of people have watched him for more than a decade on TV, and he is part of the celebrity culture and he will stay whatever he wants to say."

Clinton also said some of Trump's more questionable claims may actually help him with a slice of the electorate which is simply interested in the real-estate mogul's outspoken nature.

"If he's held account, that it's not true, he just brushes it off and he goes on," Clinton said. "And I think that, you know, there's a certain attractiveness to people that here's a guy who says exactly what he believes, untrue as it may be, inflammatory as it certainly is."

"Who can agree with anything he says that is subject to one second of fact-checking?" Clinton added.

Polling analysts have suggested throughout the Republican primary race that much of Trump's strength has come from his high name recognition. But some now say that his durability in the polls suggests a deeper appeal with a large segment of GOP primary voters.

Asked about Trump's popularity earlier this year, former President Bill Clinton had a slightly different take.

In an appearance on "The Late Show," the former president said Trump's allure among some Republican primary voters was rooted in his promise to easily solve large national problems through sheer will and skilled negotiation.

"He's a master brander, and he's the most interesting character out there, and because he says something that overrides the ideological differences," Bill Clinton told host Stephen Colbert.

He added: "There is a macho appeal to saying, 'I'm just sick of nothing happening. I'm going to make things happen. Vote for me.'"