RALEIGH, NC -- Hillary Clinton has employed a large group of high profile surrogates including President Obama to campaign across the country ahead of election day, but none of the surrogates have been more effective at making the case against Donald Trump than first lady Michelle Obama.

Clinton's campaign announced Sunday that the two women will campaign together for the first time on Thursday in North Carolina.

"She has exceeded our expectations in terms of how many events she has been able to do, willing to do," Clinton press secretary Brian Fallon said of the first lady. "Her team keeps surprising us with additional availability and we can't, from our vantage point, we can't get her out there enough. She's been an absolute rock star."

So far, Michelle Obama has appeared for Clinton six times since the first lady gave a powerful speech on night one of the Democratic National Convention. At a speech earlier this month in New Hampshire, Obama said that Trump's remarks about how he women will let him do "anything" because he is a "star" heard in a leaked video have "shaken me to my core," and she called on voters not to dismiss them as "just another day's headline."

"Last week we saw this candidate actually bragging about sexually assaulting women. I can't believe I'm saying that a candidate for president of the United States has bragged about sexually assaulting women," Obama said.

The first lady has drawn large crowds at her events in battleground states, making a trip to Arizona on Thursday where 7,000 supporters came out in the middle of the day. Never mentioning Trump's name, the Obama has had so much impact that she seemed to get under the Republican nominee's skin.

Trump brought up a speech Obama gave during the 2008 primary when her husband was running against Clinton and interpreted the remark as a hit against Bill Clinton's affairs.

"I see how much [Michelle Obama] likes Hillary," Trump said at a rally in North Carolina. "But wasn't she the one that originally started the statement, 'If you can't take care of your home,' right? 'You can't take care of the White House or the country?' Where's that? I don't hear that. I don't hear that."

The first lady claims her 2008 remark was about balancing family and politics and not an attack on Clinton.

"In light of this joint appearance, if he wants to resort to that again, we’ll see how that works out for him," Fallon said.

"She's one of the most admired people in America period. And I think it's exceptional to have the opportunity to have a strong woman like the first lady attest to another strong woman like Hillary Clinton who is running for president," he said. "In terms of the idea that voters are looking for someone who they can envision as a role model in the job of president is something that is a really effective way to make the case as to why Donald Trump is unacceptable."

Fallon added that Michelle Obama has become their "not-so-secret weapon" and as Clinton spends more time in North Carolina, a place the Clinton campaign considers a must-win for Donald Trump, they believe Obama will help make the case.