NASHUA, N.H. — Former President Bill Clinton made his debut solo appearance on behalf of his wife's 2016 presidential campaign in New Hampshire Monday — a lot grayer, a bit trimmer and far more subdued than nearly a quarter-century ago, when he rescued his flagging 1992 campaign in this key early voting state.

While Bill Clinton was keen to keep the focus on Hillary Clinton's key campaign platforms, the passing time hasn't shielded him from the ghosts that haunted his own presidency. Republican front-runner Donald Trump has gone on the offensive in recent days with attacks over his impeachment and decades-old sex scandal.

Both Clintons aimed for higher ground, even on policy. Asked in Cedar Rapids, Iowa, about Trump's remark that Hillary Clinton helped create the Islamic State group, she replied: "I've adopted a New Year's resolution. I'm going to let him live in his alternative reality and I'm not going to respond."

In Manchester, N.H., meanwhile, Bill Clinton mingled with a lunchtime crowd at a popular eatery while a news station playing above his head ran captioned video questioning whether he could avoid Trump's flagrant attacks — and that's just what he did.

"They have to choose a nominee and we have a primary to win," he said when asked about Trump and the broader Republican field. "One of my many rules in politics is don't look past the next election."

In a wide-ranging address that took voters through Hillary Clinton's work as a young lawyer in Arkansas, ways to combat heroin addiction, the political achievements of President Barack Obama and the failings of America's fourteenth president, Franklin Pierce, Bill Clinton argued that the Democratic front-runner offers the best plan to restore "broadly shared prosperity."

The two-term president seemed in his element making small talk and posing for dozens of photos.

"He practically sat in my lap," said Denise McMann, who was having lunch with her three sisters. "I'm not supporting his wife. But he was the former president, so it's exciting."

The event marked the former president's debut solo appearance for his wife, part of a broader strategy to boost her campaign in the run-up to early voting next month. Clinton's campaign later announced that the ex-president would make campaign stops in Iowa on Thursday.

"I do not believe in my lifetime anybody has run for this job at a moment of great importance who was better qualified by knowledge, experience and temperament to do what needs to be done now," he told several hundred New Hampshire voters gathered in a college auditorium.

Trump was on the offensive ahead of Bill Clinton's campaign debut, raising concern over the former president's scandals and the role his wife played.

"I don't really care about Monica Lewinsky other than I think that Hillary was an enabler and a lot of things happened that were obviously very seedy," Trump said in an interview with CNN Monday. "I mean, he was impeached, for heaven's sake. He was impeached over this stuff."

In 1998, the House voted to impeach, or formally accuse, then-President Clinton of perjury and obstruction. In February 1999, the Senate acquitted him.

Trump steered clear of attacking the former president at a rally in Lowell, Massachusetts, Monday evening, although he did mock Hillary Clinton for using "the biggest teleprompters I've ever seen."

So far, Bill Clinton has remained silent on Trump's slams — following the lead of his wife's campaign, which believes its candidate comes across as more presidential by rising above what they see as the Republican's crass political tactics.

The former president spoke calmly and quietly in New Hampshire, methodically describing the issues he sees as motivating voters in the next election. Clinton warned voters that the next president could appoint as many as three Supreme Court justices and reverse the health care law and environmental programs of the Obama administration.

Hillary Clinton, her husband said, offers the best path to economic prosperity, dealing with social problems like heroin addiction and promising a foreign policy that doesn't undermine the American character.

Still, some of Trump's attacks seem to have struck a nerve.

At a campaign event in New Hampshire on Sunday, Katherine Prudhomme O'Brien heckled Clinton about her husband's sexual history, accusing her of enabling him to mistreat women.

"You are very rude and I'm not going to ever call on you," Clinton snapped at O'Brien, after repeated shouted interruptions by the New Hampshire state representative.

The Clintons' schedules Monday showed the degree to which the ubiquitous political couple will be able to blanket the early primary states in the next two months as Democrats hold contests in Iowa, New Hampshire, Nevada and South Carolina.

While the former president was drumming up support for his wife in New Hampshire, Hillary Clinton was starting a two-day "river-to-river" tour of Iowa, holding town hall meetings and organizing events across the state.

Bill Clinton's longstanding ability to raise money will also be an asset in the weeks ahead, with fundraisers on the calendar in New York, Seattle, Phoenix, Albuquerque, N.M., Cleveland and Fairfield, Conn. The couple's daughter, Chelsea Clinton, is also getting into the act, headlining fundraisers of her own in Boston, Atlanta and Chicago next week.