Trump's strategy of attacking Bill Clinton may not work: Experts

US Republican front-runner Donald Trump has said former president Bill Clinton was a fair target, begging the question of whether that could hurt his possible Democratic rival Hillary Clinton, according to a media report.

The bombastic billionaire is well known for saying anything and everything that comes to mind, and has often sparked controversy for his outrageous comments, which critics deride as obnoxious. However, Trump has maintained a solid lead over other Republican candidates so far in polls, Xinhua reported.

Trump said earlier this week that Hillary's husband Bill Clinton was "fair game", and that Bill Clinton had a past sullied by sexual misconduct and "abuse of women".

He underscored Clinton's affair with ex-White House intern Monica Lewinsky, with whom the former president had an affair that grabbed global headlines.

Trump's assault came on the heels of Hillary Clinton's assertions that she would use her "secret weapon" Bill Clinton to help her clinch the White House in 2016.

Trump responded by a message on Twitter: "If Hillary thinks she can unleash her husband, with his terrible record of women abuse, while playing the women's card on me, she's wrong!"

But some experts said Trump's strategy may not work to hurt Hillary Clinton's presidential campaign.

Hillary Clinton, also a former secretary of state, is boasting a comfortable lead over her Democratic rivals to clinch the party nomination, and is well poised to defeat Trump if he wins the Republican nomination.

Trump has alienated several crucial voting blocks with his controversial or even provocative remarks over the issues of gender, race and immigration.

"Recycling personal scandals from two decades ago won't have much relevance for the 2016 campaign. That is old news and people aren't going to be affected by that," Brookings Institution's senior fellow Darrell West told Xinhua.

Bill Clinton, despite his sexual scandals, remains very popular and many Americans appreciate the strong economy America had during the 1990s when he was president, West said.

"Trump is attempting to distract voters from his own personal issues with women," he added.

Indeed, Trump has been accused of making a number of what critics called sexist remarks, such as poking fun at rival Republican candidate Carly Fiorina's looks.

"It didn't work for Republicans in the late 1990s. In fact the public was frustrated with the GOP (Republican Party)," Julian Zelizer, professor of history and public affairs at Princeton University, told Xinhua.

"The biggest impact it can have is just to create doubts and concerns among Democrats about the Clintons and scandals. But I think the chances are it won't have a big effect and could be a distraction from more serious issues," Zelizer said.

For his part, Bill Clinton has had a history of what critics call sexual misconduct, in addition to the Lewinsky affair.

In a nationally televised interview on Dateline NBC in 1999, Juanita Broaddrick, a nursing home administrator, alleged that Bill Clinton had raped her while he was running for governor two decades prior.

Former Arkansas state employee Paula Jones filed a sexual harassment civil suit against Bill Clinton, winning an out-of-court settlement in which Clinton paid $850,000.