With nomination secured, Trump to aim all guns at Hillary Clinton

Finally, Trump is sure to dredge up her husband's numerous marital infidelities, as former President Bill Clinton was known in the 1990s for his affair with then White House intern Monica Lewinsky, plus numerous other affairs.

In speeches and public appearances, Trump has already taken to referring to Clinton as "crooked Hillary" -- a label intended to paint her as corrupt and dishonest.

"(Trump) will throw 100 pieces of mud against the wall, in hopes that something will stick and torpedo her candidacy," West said. "He will use the National Enquirer to leak unfounded stories against her," he said, speaking of a US tabloid newspaper.

Clinton already has high negatives, but they are likely to increase due to the bruising campaign, he said.

While Trump will not soften his rhetoric on Clinton, he will make an effort to appear more presidential, such as in the realm of foreign policy.

Indeed, the brash businessman recently made a foreign policy speech in which he steered clear of his usual bombast, but instead outlined several serious points in a cogent argument.

Trump hired a speech writer, and analysts argued that he appeared more presidential than usual, in a bid to start looking and playing the part of the commander in chief.

"He will do several serious policy speeches to buttress his substantive credentials. He already has done one on foreign policy and will do others as well. He needs to cross a threshold of seriousness so that people see him as a legitimate possibility for the presidency," West said.

While Clinton lost Tuesday's Indiana primary, she will more than likely still win the Democratic nomination and is looking ahead and focusing her sights on Trump.

"Hillary will not get distracted by Sanders. She is very close to winning the delegates she needs for the nomination and will devote all of her attention to Trump," West said.