Early voting and voting by mail have begun in many states and while Hillary Clinton gains in the polls, Republican presidential nominee Donald Trump took to twitter on Sunday and alleged that results were being "rigged" at many polling places.

As he had done earlier in the Republican nominating contests, Trump once again said that the electoral process is skewed, but did not cite any evidence.

"The election is absolutely being rigged by the dishonest and distorted media pushing Crooked Hillary - but also at many polling places - SAD," Trump wrote on Twitter. He has also urged his supporters to keep an eye on voting locations to prevent a "stolen" election, which some critics interpreted as encouraging them to intimidate voters.

Last week has been particularly hard for the Trump campaign as the media was flooded with the news of women accusing Trump of making unwanted sexual advances and groping them.

The Trump campaign also filed a legal response against the New York Times, which ran a piece with some accounts of the women who have made the allegations. Their legal response where they said that Trump's reputation was already "compromised' has since gone viral.

The election is absolutely being rigged by the dishonest and distorted media pushing Crooked Hillary - but also at many polling places - SAD — Donald J. Trump (@realDonaldTrump) October 16, 2016

Trump also had to defend another leaked video from 2005 at the second (Townhall) debate. In the video, he was heard making lewd and misogynistic comments. He apologised for the video during the debate and then attacked Hillary Clinton by referencing her husband Bill Clinton's sex scandal that broke in 1998 that led to his impeachment.

Meanwhile, Reuters-Ipsos States of the Nation project released its polls on Saturday, which predict Clinton's odds of securing the 270 Electoral College votes needed to win the presidency at more than 95 percent and with a sizeable margin of 118 Electoral College votes.

According to the project, Trump trails by double-digits among women and all minority groups.