Donald Trump sends brutal message to Joe Biden as he flies into DC to speak to Christian voters before MAGA rally in Philadelphia tonight

Donald Trump claims the U.S. is 'finished' if he loses the election and 'crooked Joe' Biden stays president.

The former president talked up his rally on Saturday night in a video message recorded from his private jet, 'Trump Force One.'

Trump said he was on his way to Washington, D.C., for a Faith and Freedom Coalition event where he would give a speech to Christian voters.

Straight afterward, he would get back on the plane and hop to Philadelphia for a rally, which he said would be on most TV channels.

'It's very simple, if you get ratings they (TV stations) pick it up, if you don't get ratings they don't pick it up,' he said.

Trump then bragged that a new poll had him 10 percent ahead of 'crooked Joe Biden, the worst president in history'.

'November 5th will go down as the most important, most consequential day in the history of our country,' he said of election day.

'We have to win, if we don't win, this country is finished.'

Trump was referring to a Rasmussen poll released on Friday that had him ahead 46 percent to Biden's 36 percent in a five-way race.

Independent candidates Robert F Kennedy Jr and Cornel West had nine and two percent each and Jill Stein of the Greens had just one percent.

Trump was also ahead 49 to 40 percent in a two-way race with Biden, with seven per cent saying they would vote for someone else and four percent undecided.

Rasmussen historically skews to conservative candidates and the poll is an enormous outlier compared to other recent results.

Biden has a tiny lead in the FiveThirtyEight average of recent national polls, while Trump has slender advantages in the more sporadic polls of battleground states.

The president is locked in five days of debate preparation at Camp David before the two rivals go head-to-head on Thursday night.