PHOENIX - First Lady Michelle Obama will make a campaign stop in Phoenix Thursday for Hillary Clinton, Clinton campaign manager Robby Mook said on a conference call with reporters Monday.

Obama's visit would come after campaign stops in Arizona this week by Chelsea Clinton and Sen. Bernie Sanders. Sanders will be in Flagstaff and Tucson on Tuesday, and Chelsea Clinton will be at Arizona State University on Wednesday.

The Clinton campaign is also investing $2 million in TV ads, digital ads and direct mail in Arizona, Mook said.

The huge push in Arizona comes the same week voters get their mail-in ballots.

"Donald Trump's hateful rhetoric and deeply disrespectful remarks about Sen. John McCain have made Arizona more competitive," Mook said.

Arizona "is a state that would foreclose a path for Donald Trump to win the White House," Mook said.

Polls show the Arizona race between Clinton and Trump is a tossup. Only one Democratic presidential nominee has won Arizona in the last 68 years -- Bill Clinton, in 1996.

"We do see opportunity in Arizona, but we do think that is an uphill climb," Mook said.

Regarding the U.S. Senate race in Arizona between Democratic Congresswoman Ann Kirkpatrick and Republican Sen. John McCain, Mook did not list Arizona among several Senate battleground states where the Clinton campaign is providing support.