From Las Vegas, Nevada -

With less than three weeks to go to Election Day, Hillary Clinton and Donald Trump will square off in their final Presidential debate, as Trump is again grabbing headlines with his invited guests, as he tries to score points against both the President and Mr. Obama's former Secretary of State.

"(Wednesday) is going to be an interesting night," Trump said to cheers at a Tuesday rally in Colorado, where he again mocked Clinton's light campaign schedule since the last debate.

"She's home sleeping and I'm working," Trump said, much to the delight of his audience. "That's the way it's going to be in the White House, too."

In the last debate in St. Louis, Trump grabbed headlines by bringing in three women who had accused Bill Clinton of sexual assault; this time, he is bringing in the mother of one of those who died in the Benghazi attacks, along with President Obama's half-brother.

Malik Obama has publicly said he is supporting Trump; but it wasn't readily apparent how the President's half-brother would be a boost for Trump here at the debate.

The Clinton campaign's chief spokesman all but mocked Trump over the move, which came hours after President Obama had told Trump to "stop whining" about a 'rigged' election.

It wasn't clear if Trump would bring other controversial guests, but there were a number of rumors circulating in Vegas.

"Trump team looking at additional debate guests to try to rattle Clinton," said New York Times reporter Maggie Haberman on Twitter.

Along with two stops in Colorado on Tuesday, Trump's campaign released a new television ad that hit Hillary Clinton on the issue of "change" - and left many election watchers wondering why Trump has not been pounding solely on this same theme for months.

"Donald Trump's most on-message spot of the cycle," said political analyst Mark Halperin.

"And exactly what he (Trump) should be saying every day and night. But somehow cannot," said Steven Lombardo, the PR chief at Koch Industries, a group that has steadfastly refused to back Trump.

"Why hasn't this Trump ad run every day in every swing state since June?" asked James Pindell, a top political reporter at the Boston Globe.

Message discipline though, has never been one of the strong suits of Donald Trump during this campaign; he has improved at times by using a TelePrompter, but often stepped on his message by going off script.

As for Clinton, she has done little campaign work in recent days; since the last debate on October 9, Clinton has only done a half dozen public campaign stops.

One would expect that Clinton will play defense in this final debate, as Donald Trump is the candidate who needs a "magic moment" to boost his campaign.

Since the last debate, her poll numbers have seemed to solidify both nationally and in many key state polls.

The main reason could be simple - she's holding on to the support of more voters in her own party.

Pollster Mark Blumenthal admitted some of the polls seem "odd," like those that have shown strength for Clinton in typical red states like Georgia and Texas.

But when you add into the mix a growing edge among Independent voters, that is all coming together at this point to further boost Clinton.

The latest poll from Fox News showed Clinton with a 38-31 percent edge among Independent voters, all part of a 9-point edge for Clinton nationally.

Trump - who loves to talk about polls that show him ahead - was discounting many of the polls during his stops in Colorado, as he said it's all part of the news media's effort to "fix" this election.

"They always show the bad polls," Trump said.