Hillary destroyed many women’s lives than her husband: Trump

An unrestrained Donald Trump has launched a full-scale personal attack on Hillary Clinton, saying she has been an "unbelievably nasty, mean enabler" of her husband's abusive behaviour against women, raising once again former President Bill Clinton's marital infidelities.

His comments, at a rally in Oregon, marks the sharpest tone Trump has used against his Democratic rival after he became the presumptive Republican presidential nominee.

This also was the first time in months when Trump, whose derogatory remarks for women have fuelled his deep unpopularity among female voters, has been so direct in referring to the former president's affairs.

"She's been the total enabler. She would go after these women and destroy their lives," Trump said of Clinton.

"She was an unbelievably nasty, mean enabler, and what she did to a lot of those women is disgraceful."

Trump, a real estate billionaire from New York and the only candidate left in the Republican race to the White House, is likely to face Clinton, who has made New York her adopted state, in the November general elections.

At another rally in Washington, Trump continued his tirade against the Democratic frontrunner, saying "Hillary Clinton's husband abused women more than any man that we know of in the history of politics."

"Hillary hurt many women. The women that (Bill) abused. Some of those women were destroyed not by him, but by the way that Hillary Clinton treated them after everything went down," he said and claimed he respects women more than anyone else.

"There is nobody that respects women more. I have women, frankly - I shouldn't say this, because the men are going to get angry - but I have women that make more money than men doing a comparable job," Trump said.

There was no response from the Clinton campaign, which has refused to get involved in personal allegations.

Trump's comments came as part of a defence against recent attacks from Democrats focused on his controversial comments and stances on women's issues. He has been criticised for his "demeaning" remarks against the wife of former party rival Ted Cruz and a Fox News woman anchor who questioned him sharply on his penchant for making crude remarks toward women.

Clinton this week in an interview to CNN described Trump as a loose cannon, while President Barack Obama has called for a scrutiny of the presumptive nominee's policies and record.

Trump, a former reality star who joined politics only 10 months ago, has however defeated 16 Republican candidates many of whom well-established governors and senators. He is now facing an open revolt from establishment Republicans.

House of Representatives Speaker Paul Ryan has said he is not ready to support Trump yet.

Several former presidential candidates - including Jeb Bush and Lindsay Graham - have said they would not vote for Trump, thus raising questions over his capacity to unite the party in a crucial election year.

Trump, in his characteristic style, responded saying he is not duty-bound to unify the party. "Does it have to be unified? I'm very different than everybody else, perhaps, that's ever run for office," Trump told ABC News.