Days before Bill Clinton is scheduled to hit the road to campaign for his wife, Donald Trump again stepped up his attacks on the former president's past sexual misconduct and his controversial comments during the 2008 Democratic nomination fight.
"You look at whether it's Monica Lewinsky or Paula Jones or many of them," Trump said on NBC's TODAY. "That certainly will be fair game. Certainly if they play the woman's card with respect to me, that will be fair game."
In recent days, the GOP front-runner has been highlighting the former president's affair with intern Monica Lewinsky, saying that Bill Clinton has a pattern of "abuse of women."
And he has referenced the long and brutal primary fight between Barack Obama and Hillary Clinton in 2008, when Bill Clinton's efforts to advocate for his wife largely backfired -- particularly with minority voters.
The former president weathered heavy criticism in January 2008 after comparing Obama's impressive primary performance in South Carolina, which has a large African-American voting bloc, to Jesse Jackson's success in the state.
Earlier that year, he referred to Obama's record on Iraq as "the biggest fairy tale I've ever seen." And in April 2008, he suggested that the Obama campaign "played the race card on me."
Bill Clinton is scheduled to make his first campaign appearance of 2016 in New Hampshire next week.
The news of the former president's planned stops prompted a late-night tweet from Trump on Monday.
And on Tuesday, Trump reiterated that claim, although he clarified that he does not believe Bill Clinton perpetrates racism.
"They called him a racist. I don't believe he is a racist if you want to know the truth, but they called him a racist," he said of the 2008 controversy.
Clinton's team has said that the campaign won't be distracted by the attacks.
"Though Donald Trump has pushed around nearly all of his fellow Republicans, Hillary Clinton won't be bullied or distracted by attacks he throws at her and former President Clinton," Clinton campaign spokeswoman Christina Reynolds said in a statement to NBC News.
Trump has spent almost no money on advertising so far in the race, a marked contrast to opponents like Jeb Bush and Marco Rubio.
But he indicated at a rally Monday night that he plans to dramatically boost his spending after the first of the year.
"We're going to spend a lot of money over the next four weeks," Trump said. "We just don't want to take any chances, we're too close."
That ad buy could reach about $2 million per week, FOX News reported. That would bring Trump to parity with Rubio and Bush's efforts. The two campaigns - and their affiliated super PACs - are already spending more than $2 million weekly.
So far, Trump has spent just $217,000 on radio ads, with no television presence at all to date.
This article first appeared on NBCNews.com.