LOWELL — After days of publicly questioning Bill Clinton's personal past, GOP front-runner Donald Trump did not utter his name Monday night during a rally that took place just 20 miles and a few hours away from the former president's earlier appearance in New Hampshire.
Trump, speaking before a crowd in Lowell, instead directed his criticism toward Clinton's wife, current presidential candidate and former secretary of state Hillary Clinton.
"She has the biggest teleprompters I've ever seen," Trump said. "We don't need four more years of Obama, and that's what you're getting with Hillary. And I believe it might be even worse, to tell you the truth. But I speak from the heart."
Bill Clinton, making his first solo appearance Monday to campaign for his wife in New Hampshire, likewise avoided engaging with Trump. Clinton's visit came as Trump has begun drawing the former president's extramarital scandals into the campaign conversation.
On Monday, Trump told CNN that Clinton was "one of the great women abusers of all time."
But Trump made no such comments at the Paul E. Tsongas Center at University of Massachusetts Lowell on Monday evening, delivering a blustery and wide-ranging rallying cry that was frequently interrupted by protests inside the arena. Trump chided Clinton's campaign for "the money they spent" building out her campaign headquarters in Brooklyn, N.Y. He shot back at Clinton for criticizing his tone in the race.
"I'm a much nicer person that she is, but we have to be tough," Trump said.
Trump's boisterous speech — during which he criticized top Republicans including House Speaker Paul Ryan and strategist Karl Rove — contrasted with Bill Clinton's softer approach earlier in the day. Speaking in an almost subdued voice, Bill Clinton indicated that, even for a central figure in the Washington acrimony of the 1990s, the current campaign environment had grown too hot.
"I don't fit anymore," he told the hundreds gathered in a gymnasium at Nashua Community College. "First of all, I'm a happy grandfather. I'm not mad at anybody."
All but ignoring the criticism trained on Hillary Clinton by the Republican field, Clinton focused on policy and Hillary Clinton's desire to help people.
Echoing one of his wife's campaign pillars over the last several months, Bill Clinton also highlighted the opioid epidemic that has hit the country, saying three of his friends had lost kids to addiction.
Trump also mentioned the crisis in his speech, calling it a "real problem" that he's often asked about during his visits to New Hampshire and Massachusetts.
When a reporter asked Clinton during a Manchester diner stop about the former president calling the Republican field "scary," he offered a parsing response, qualifying that it was not the candidates themselves but their debate that he had labeled as frightening.
"I said that their debate was scary; that means I disagreed very strongly with a lot of what they're saying," Clinton said. "But they have to decide where they want to take the country, they have to choose a nominee. And we have a primary to win."
Asked about Trump by a reporter later in the day at the Puritan Backroom in Manchester, Clinton declined to comment. And in four campaign stops across the state, apart from briefly likening former House majority leader Tom DeLay to Senator Ted Cruz of Texas, who is leading some Iowa primary polls, Clinton avoided direct mention of either his wife's chief primary rival, Senator Bernie Sanders, or any of the Republican presidential contenders.
The Clinton campaign's strategy so far has been, essentially, to turn its back to Trump's assertions.
On Sunday, Hillary Clinton declined to respond to allegations shouted by a Republican state representative at a town-hall-style meeting in Derry about the former president's sexual indiscretions.
The public rancor between Trump and the Clintons did not always exist. Both Clintons attended Trump's 2005 wedding in Palm Beach, his third marriage.
Trump donated to the Clinton Foundation, both he and Bill Clinton have said. They have played golf together.
Trump has said he had good personal relationships with politicians of all stripes because it was lucrative for his various businesses and because they wanted his financial donations.
The former president's return to the state that helped resuscitate his 1992 campaign also comes amid a flurry of candidate visits to New Hampshire. Seven candidates campaigned in New Hampshire on Monday, including Sanders, who held an event 25 miles from one of the former president's stops.
While polling in the state has shown erratic results, some surveys give Sanders a substantial lead over Hillary Clinton.
Trump is scheduled to return to the state Tuesday for a rally in Claremont.
While still popular in the Democratic Party, Bill Clinton is far from a guaranteed asset on the campaign trail.
In 2008, as the Democratic primary pitting Hillary Clinton against Barack Obama ground on, Clinton made a string of statements that angered the party's base and put her campaign on the defensive.
Clinton's "Big Dog" persona has also been unleashed on behalf of Obama's presidency, memorably during a visit to the White House briefing room in December 2010 to argue for a tax cut deal with congressional Republicans and again during the 2012 Democratic National Convention in Charlotte.
But Clinton appeared intent on avoiding any measure of controversy on Monday.
A retail stop at the Puritan Backroom appeared to put Clinton in a more comfortable setting, allowing him to tell stories about the 50th anniversary of the Normandy invasion and chat with diners about his favorite meals — chili with spaghetti — back before doctors had encouraged him to eat more healthfully.
He chatted with members of a 1957 high school graduating class who congregate there every month, stopped at the bar to watch CNN coverage of his Nashua speech, and posed for a photo with the mother of one of his Secret Service detail, along with the red-faced agent.
During an evening speech to an overflow-crowd at Exeter Town Hall, Clinton repeated many of the same themes from his Nashua speech, adding a note of praise for one of the protest movements that has entered the political conversation election season.
"I like all those young people in Black Lives Matter. I think what they're saying is important," said Clinton.
Jim O'Sullivan can be reached at jim.osullivan@globe.com. Follow him on Twitter @JOSreports. James Pindell can be reached at james.pindell@globe.com. Follow him on Twitter @jamespindell.Click here to subscribe to his daily e-mail update on the 2016 campaign.