PHOENIX - First lady Michelle Obama was at the Phoenix Convention Center Thursday to deliver a speech in support of Democratic presidential nominee Hillary Clinton.

She's the third big-name Democrat to travel to Arizona this week to campaign for Hillary Clinton. Bernie Sanders and Chelsea Clinton both rallied voters over the past few days.

The state of Arizona has voted for Republican presidential candidates since 1952 -- with the exception of Democrat Bill Clinton in 1996. However, recent polls show Donald Trump and Hillary Clinton running close here.

Obama says that Donald Trump's refusal to say he'd accept Nov. 8 election results if he loses is an insult to millions of Americans who are voting in the presidential election.

She told more than 7,000 supporters of Hillary Clinton in Phoenix -- some standing in line overnight -- that Americans decide elections and Trump was threatening to "ignore our voices and reject the outcome of this election." The first lady said that's the same as "threatening the very idea of America itself."

Trump said during Wednesday's debate that he'll keep the nation "in suspense" about whether he'll accept the vote outcome.

Mrs.Obama said: "You don't keep American democracy in suspense."

Obama also said Trump can't see the human beings inside people who are different from him.

She said "maybe that's why he calls communities like the one where I was raised, 'hell:' Because he can't see all the decent, hardworking folks like my parents."

She suggested that Trump's life in a tower in New York City has kept him away from regular Americans.

The first lady was born in Chicago to a city water plant employee and a homemaker. Michelle Obama went to Princeton and Harvard, where she got her law degree.

While she was in Phoenix, her husband was speaking at a rally in Florida. He encouraged voters to take advantage of early voting, beginning Monday, saying you can "reject somebody who proves himself unfit to be president every single day in every single way."