LAS VEGAS (WPVI) --Both Hillary Clinton and Donald Trump need a home run in the third debate.
They each need to fire up their base to make sure they get out to vote.
Professor Randall Miller of St. Joseph's University says it's all about looking presidential, talking about issues and trying to control the news cycle.
Miller says Trump has to stop his scorched earth problem.
"He not only comes across as somebody who is out of control, feeding the other side as well, but it distorts the message, it muddies everything up, it confuses people," Miller said.
Miller says Trump has a powerful message that is still resonating for many people: he's running against Washington and the establishment.
WATCH: The debate stage is set
Miller says the collateral damage Trump has suffered with the sexual accusations is deep. But Miller thinks Trump can still win if he continues crisscrossing the country to campaign.
"He needs to come out, establish his themes, stick to the message, show that he's in control," Miller said.
Clinton has a different set of challenges.
She still can't get some voters to trust her and Bernie Sanders' supporters along with other millennials may not bother coming out on November 8.
"They can't support Clinton because they say she is a tool of Wall Street, she is untrustworthy, and all the other things," Miller said.
Miller says Clinton needs to hope Trump continues being Trump, so that voters focus on his defects rather than their questions about her.
"She needs to make people believe in her or believe in her enough that they're actually going to do that last thing, they're going to pull the lever for her, whatever misgivings they have," Miller said.
Watch the Presidential Debate beginning at 9 p.m. Wednesday on 6abc.