The Democratic Party's lurch to the left is much like the disruption Republicans felt about decade ago with the rise of the tea party on the far right, former House Speaker John Boehner told CNBC on Friday.
"It's their turn in the barrel," said Boehner, a Republican who had served for 24 years as a congressman from Ohio. "What Democrats are going through in 2016 and 2018, with the progressive movement, Republicans went through in 2010 and 2012 with the tea party movement."
The austerity-minded tea party, aimed at reducing the size of government, started after CNBC commentator Rick Santelli went on a tirade in February 2009, criticizing then-President Barack Obama's mortgage bailout plan. The rant came about a month before the financial crisis bottom in the stock market.
The staunchly conservative wing of the Republican Party, which has basically shed the tea party moniker but remains powerful to this day, targeted the more moderate Boehner in the months leading up to his abrupt resignation from Congress in 2015. He said at the time, "Prolonged leadership turmoil would do irreparable damage to the institution."
In Friday's "Squawk on the Street" interview, Boehner said he would not hazard a guess as to which candidate would win the 2020 Democratic nomination. But he did say, "It looks pretty obvious that it's going to be someone that I would describe as on a more progress side."
Vermont Sen. Bernie Sanders, a self-described democratic socialist, is widely seen as the inspiration of the current progressive movement. In 2016, he fired up the grassroots of the Democratic Party before ultimately losing the party's presidential nomination to Hillary Clinton. However, the excitement around Sanders disciples, like New York freshman Rep. Alexandria Ocasio-Cortez, helped flip the House Democrat in the 2018 midterm election.
Sanders last month announced he's running for president again, joining another champion of the left, Massachusetts Sen. Elizabeth Warren, and a host of current and former lawmakers and others seeking the Democratic nomination.
"My guess is they'll nominate someone that's very far left, and in my view out of step with where the American people want to go. And thereby increasing the chances of Donald Trump being re-elected, assuming that he runs," said Boehner.
There has been speculation here and there about Trump's commitment to seeking a second term. But the president has given every indication that he's running for re-election, a campaign that got officially underway with a Federal Election Commission filing on the day he was inaugurated in January 2017.