Watch Lindsey Graham for hints Trump is losing his 'grip on the party': former GOP lawmaker

In a deep dive into his life after his political career collapsed with an assist from Donald Trump, former South Carolina Gov. Mark Sanford (R) described to The Guardian's David Smith how the ex-president helped drive him out of the party and how the public will know when the party is done with Trump.

Keep an eye on Sen. Lindsey Graham (R-SC), he advised.

Sanford -- who memorably became involved in a marital scandal after he told his staff he was "hiking the Appalachian trail" when he instead was in Argentina with a woman who was not his wife -- finished out his second term as governor in 2011 before taking two years off and then winning a seat in House. His stay in the House, however, was short-lived after Trump became president in 2016 and Sanford failed to fully support him.

Speaking with Smith, Sanford explained, "In a cosmic sense, it's like, God, is this just a cruel joke? I went through a rather humbling journey post-2009 wherein, needless to say, within the GOP there were some folks who felt strongly that I'd let them down, which I had … And then fast forward and along comes a guy who personifies all of the opposite things that I thought God and circumstance and other people were trying to teach me post-09. And this guy is running for president? And then he gets the nomination and then he becomes president."

As for Trump's hold over Republicans, Sanford speculated that it is as strong as it has ever been and claimed his former South Carolina GOP colleague, Lindsey Graham, can be used as a barometer to gauge Trump's decline.

"We started in Congress together and he's very much of a different school on these kinds of things and adapts where he needs to adapt to hold power," Sanford told Smith. "But I would use him as a canary in the coalmine and the degree to which he has doubled, tripled and quadrupled down on Trump says everything. Whether you like him or not, he has a good political nose for his base. He knows South Carolina well and his reading the tea leaves is not to be dismissed."

Sanford closed his interview with Smith by taking a shot at the Republican Party that he asserts changed due to Trump.

"I am a citizen with no country," he lamented. "I am an unabashed conservative in the Jeffersonian sense and right now, if you believe in those ideals, you certainly don't find it in the Republican party and it's even been lost within the movement itself of late because there is no movement."

You can read the whole interview here.