Trump told the crowd to vote with urgency and "pretend we're slightly behind," though some recent Florida polls do show him trailing Clinton. He added, "We don't want to blow this."
At one point, Trump appeared to single out NBC News reporter Katy Tur for criticism, as he has done before.
"We have massive crowds. There's something happening. They're not reporting it. Katy, you're not reporting it, Katy. There's something happening, Katy. There's something happening, Katy," Trump said.
As animosity against the media has grown at recent Trump rallies, his has added a larger buffer zone and more security between reporters and the crowds. But at the Miami rally, there was no buffer, and screaming supporters were just inches away from reporters. One man near the press pen continued screaming menacing things at "Katy" as the rally continued.
Meanwhile, President Barack Obama expressed concern in a radio interview broadcast that too few African-Americans are voting this time around, and he pressed black voters to turn out for Clinton to protect the policies he has implemented.
"I'm going to be honest with you right now, because we track - we've got early voting, we've got all kinds of metrics to see what's going on. And right now the Latino vote is up, overall vote is up, but the African-American vote right now is not as solid as it needs to be," Obama said on "The Tom Joyner Morning Show," a syndicated programme with many African American listeners.
Obama framed the election as not only a race between Clinton and Trump but one in which his record is on the line.
"I need everybody to understand that everything we've done is dependent on being able to pass the baton to somebody who believes in the same things I believe in," the president said.
Obama also briefly addressed for the first time the FBI's reopened investigation into Clinton's emails, saying in an interview with NowThis News that the agency does not "operate on innuendo" and emphasising that there is no evidence that the Democratic presidential nominee had violated the law.
The Clinton campaign announced that it is doubling its Arizona advertising investment to US$1 million for the final week of the campaign. A Democratic nominee for president has not won Arizona since Bill Clinton in 1996, but polls show a competitive contest there.
Trump's children were fanning out across key battlegrounds to campaign on his behalf. Donald Trump jnr, Ivanka Trump, Tiffany Trump and Eric Trump were covering Colorado, North Carolina, Michigan, Ohio and Pennsylvania.
At his rally, Trump criticised both Bill and Hillary Clinton, saying, "If Hillary Clinton were to be elected, it would create an unprecedented and protracted constitutional crisis. Haven't we just been through a lot with the Clintons? Right? Remember when he was impeached for lying? He can't practice law, he doesn't have the right to practice law. Didn't we just go through this?"
As Trump spoke, a man in the crowd kept screaming, "He's a rapist!"
LATEST POLLS
Florida
CNN - Clinton 49, Trump 47
Quinnipiac - Clinton 46, Trump 45
TargetSmart - Clinton 48, Trump 40
North Carolina
Quinnipiac - Clinton 47, Trump 44
Ohio
Quinnipiac - Trump 46, Clinton 41
Pennsylvania
Quinnipiac - Clinton 48, Trump 43
Monmouth - Clinton 48, Trump 44
CNN - Clinton 48, Trump 44
Susquehanna - Clinton 45, Trump 43
Nevada
CNN - Trump 49, Clinton 43
Political Polls - Clinton 45, Trump 38
Arizona
CNN - Trump 49, Clinton 44
Michigan
Mitchell - Clinton 50, Trump 43
Virginia
Winthrop - Clinton 44, Trump 39
Wisconsin
Marquette Law School - Clinton 46, Trump 40
Colorado
Emerson - Clinton 44, Trump 41
Political Polls - Clinton 44, Trump 37
