With only four weeks until Election Day, Donald Trump and Hillary Clinton hit the campaign trail in key states on the day after their second Presidential debate, both candidates taking direct aim, once more making the case that the other was not fit for the Oval Office.

At a stop in Michigan, Clinton wasted no time in bringing up Trump's explanation for his remarks on a 2005 video tape that surfaced last Friday.

"Donald Trump spent his time attacking when he should have been apologizing," Clinton said to cheers, as she mocked his explanation that it was nothing more than "locker room" banter.

"Now, men and women across America know that is just a really weak excuse for behaving badly and mistreating people," Clinton said to cheers from the crowd.

Clinton also hit Trump's debate answers on his taxes, and on whether he's been using cheap foreign steel for his construction projects.

"If he wants to make American Great Again, then start by buying American steel for his construction projects," Clinton said to cheers.

A few minutes later outside Pittsburgh, Trump returned the favor.

"All she could do was lie - she lied so much last night," Trump said to cheers, as the chant, "LOCK HER UP!" broke out when he mentioned Clinton's answers on her private email server while Secretary of State.

"Special prosecutor here we come," Trump said, repeating his call last night to start an investigation - "if I win, we're going to appoint a special prosecutor."

Trump also drew laughs as he speculated about who might be able to find Clinton's emails.

"I wonder if the NSA has her emails - you think?" Trump asked.

Trump also rattled off a list of differences with Clinton on the issues, zeroing in on newly leaked emails from a top Clinton aide made public by Wikileaks.

"She's for open borders and open trade," Trump said, arguing it will doom the economy of Pennsylvania and other states if Clinton is elected.

Trump also rolled out a new attack line today, arguing that Clinton would cut Social Security and Medicare benefits.

"She wants to knock the hell out of your Social Security," Trump said.

Trump also continued his attacks on former President Bill Clinton as well.

"Bill Clinton sexually assaulted innocent women and Hillary Clinton attacked those women viciously," Trump said as he vowed to keep up the attacks on if the news media releases more tapes about him.

"If they want to release more tapes (with me) saying inappropriate things, we'll continue to talk about Bill and Hillary Clinton," Trump said to cheers, as he accused the news media of covering up the misdeeds of the Clintons - and Ted Kennedy.

"We're going to fight," Trump said to cheers, as this campaign seems like it is going to have an animated next four weeks.