Presumptive Republican nominee Donald Trump has shifted his attention to the US general election, away from his fallen GOP rivals and on to Hillary Clinton – who is favoured to win the Democratic nomination.

But despite this shift in scope from states to the nation, not much else has changed in Mr Trump’s demeanor. The real estate mogul has continued to use his tactic of insults and snide nicknames that helped take down his GOP opponents – and not only towards Ms Clinton, but at another prominent woman in the Democratic party, Massachusetts Senator Elizabeth Warren.

In a campaign appearance in Oregon, Mr Trump targeted Ms Clinton after she criticised him for his stance on women’s issues. In response, the former reality TV star asserted that she was, in fact, the bad choice for American women due to how he says she treated women involved in her husband Bill Clinton’s past infidelity.

Donald Trump speaks at a campaign rally in Eugene, Oregon

“She's been the total enabler. She would go after these women and destroy their lives,” Mr Trump told the audience. “She was an unbelievably nasty, mean enabler, and what she did to a lot of those women is disgraceful.”

Mr Trump did not give specific examples, adding: “Have you ever read what Hillary Clinton did to the women that Bill Clinton had affairs with? And they're going after me with women?”

The New York tycoon then turned to speak out against Ms Warren, following her blunt criticism of the candidate following his Tuesday night victory in Indiana.

“[Donald Trump] has built his campaign on racism, sexism, and xenophobia,” she said.

In Mr Trump’s response some three days following, he called Ms Warren “goofy” and “a goofus” saying that she has done nothing for the US since she was elected to the Senate in 2012.

“I think that Hillary should run with ‘goofy’ Elizabeth Warren,” he said. Ms Warren has been the subject of some speculation as to whom Ms Clinton will choose as a running mate if nominated. “I would love to beat them.”

He continued with a barrage of attacks on her Native American heritage - an issue she faced in her 2012 campaign against then-Senator Scott Brown.

“Let’s properly check goofy Elizabeth Warren’s records to see if she is Native American. I say she’s a fraud!” he wrote.

Ms Warren shot back: “[Donald Trump] spews insults and lies because he can’t have an honest conversation about his dangerous vision for America.”

But Mr Trump continued to stoke the fire.

“Goofy Elizabeth Warren is weak and ineffective,” he wrote. “Does nothing. All talk, no action – maybe her Native American name?”

Donald Trump has yet to adopt the demeanor of a statesman this election season - despite his fulsome comments toward Texas Sen Ted Cruz after he suspended his campaign that may have suggested a tonal shift.

Mr Trump has made it as far as becoming the presumptive Republican nominee with his brand of unfiltered, unfettered rhetoric. Perhaps it could win him the Presidency.

However, Ms Warren is confident he can be beaten.

“Whatever [Donald Trump] says, we won't shut up. We won't back down. This election is too important, [and] he won’t step foot in White House.”