WASHINGTON -- The Democratic National Committee has charged the Republican National Committee and presidential nominee Donald Trump with violating a 30-year-old restriction on voting activities stemming from the 1981 New Jersey gubernatorial contest.

The suit filed Wednesday in U.S. District Court noted Trump's accusation that the election will be "rigged" and his call for observers to fan out to certain areas, namely those with a large number of minority voters. "No evidence of such fraud actually exists," the suit said.

The Democrats charged that such actions violated the consent decree agreed to by the GOP after the state party in 1981 reportedly targeted heavily minority communities that tend to support Democratic candidates.

They accused the RNC of "supporting and enabling the efforts of the Republican candidate for president, Donald J. Trump, as well as his campaign and advisors, to intimidate and discourage minority voters from voting in the 2016 presidential election."

The consent decree involves the GOP and "its agents," and the lawsuit said "Trump has enjoyed the direct and tacit support of the RNC" in his complaints about voter fraud and such efforts were directed funded by the party through its joint fundraising committee with the presidential campaign.

Trump has embraced voter identification laws that federal courts have said prevent minorities from casting ballots but Republicans have defended as necessary to prevent in-person fraud, which has been shown to be virtually non-existent.

"So many cities are corrupt and voter fraud is all too common," Trump said earlier this month in Colorado.

At the third presidential debate Oct. 19, he refused to agree to accept the election results. A day later, he said he would accept them "if I win."

Indeed, 43 percent of Trump supporters in a USA Today/Suffolk University poll released Wednesday said that if their candidate loses Nov. 8, it would be due to corruption. Just 28 percent of likely U.S. voters overall expressed that view, while 55 percent said the election would be fair and square.

During the 1981 N.J. gubernatorial campaign, state Republican officials sent letters to residents of communities with large numbers of black or Hispanic voters, and then challenged anyone whose mail was returned as undeliverable, even though they were working off outdated registration lists.

Voters in minority communities in the state were met at the polls by signs reading, "This area is being patrolled by the National Ballot Security Task Force," and by off-duty police officers and deputy sheriffs hired by the party who, according to the original complaint, "obstructed and interfered" with the normal operations of the polling places.

Under the consent decree, the RNC agreed to not undertake "ballot security activities" in areas with a large concentration of minority voters "where a purpose or significant effect of such activities is to deter qualified voters from voting."

The consent decree is supposed to end next year, but the lawsuit asks the courts to extend it for eight more years.

Jonathan D. Salant may be reached at jsalant@njadvancemedia.com. Follow him on Twitter @JDSalant. Find NJ.com Politics on Facebook