Amid her campaign's concern she's lacking support from young voters, Hillary Clinton turned to two popular surrogates Wednesday. Meanwhile, Donald Trump also turned to a top ally, whose message seemed to differ from the Republican nominee on a key issue. Josh Robin filed the following report.

Bernie Sanders again stumped for his former rival Wednesday.

"I will work with President Clinton," he said.

So did the wife of another former Clinton opponent. In an ad, and in Pennsylvania, Michelle Obama sharply blasted Donald Trump.

"And let me say, hurtful, deceitful questions deliberately designed to undermine his presidency, questions that cannot be blamed on others or swept under the rug by an insincere sentence uttered at a press conference," she said.

In Iowa, former New York City Mayor Rudy Giuliani was vouching for his nominee.

In an earlier appearance, Giuliani also softened Trump's previous position on Russia and NATO.

"He'll defend the NATO treaty. It's a solemn obligation of the United States," Giuliani said. "Yes, he's going to push some of the people that aren't paying their fare share to pay more. But that doesn't mean he doesn't understand a solemn obligation."

That's not quite what Trump has said. In July, he told the New York Times that as president, he would base military support of NATO allies on a review of their financial commitments to the organization.

Asked about observing the current treaty, Trump asked, "Have they fulfilled their obligations to us? If they fulfill their obligations to us, the answer is yes."

In his own appearances, Trump continued the attacks.

"You see all the days off that Hillary takes?" he said. "And then she can't even make it to her car."

He also made a play for Sanders supporters.

"Bernie Sanders could have gone down in the record books as being a great, great man," Trump said.

If Sanders has regrets, he isn't saying.

"And let's get out and vote and make sure that this is the next president of the United States," Sanders said.

Considering her deficit among the voters who flocked to Sanders, Clinton seems grateful.

"Isn't this one of the strangest elections you've ever seen?" she said.