Newt Gingrich is used to battling Clintons on a national stage.
In 1994, when former President Bill Clinton was in office, Gingrich was part of the so-called Republican Revolution that gave the party control of the House of Representatives for the first time in four decades. He was elected speaker and led the push for a package of legislation that included a balanced budget and tax cuts for the middle class.
But the popularity that made him a top figure in the Republican Party took a hit in 1995 when he refused to compromise with Clinton on budget talks and a fight between the country's two major parties on spending led to two unpopular government shutdowns.
In 1998, Gingrich pushed for Clinton's impeachment and removal from office after the president was accused of lying to a federal grand jury about an extramarital affair with White House intern Monica Lewinsky and obstructing justice. Clinton was acquitted.
Gingrich faced questions about his own conduct in 1999 when he was investigated by the House Ethics Committee over whether he misused tax-exempt donations. He was the only Speaker of the House to have been disciplined for ethics violations and agreed to pay $300,000 in penalties. The controversy led to his abrupt resignation from the House in 1999 after serving as a representative from the state of Georgia since 1979.
He remained visible in his post-Congress life with work as a television commentator, political consultant and author.
In 2012, he competed for the Republican presidential nomination and won primaries in Georgia and South Carolina before dropping out of the race in May of that year.
The 73-year-old has publicly supported Donald Trump in recent months, even as some prominent Republicans expressed their displeasure with the party's 2016 nominee.
"Each establishment insider to leave over Trump is further proof that Trump's program of change is real and it is their world he will change," Gingrich tweeted in June.