Poll watching is a ghost from the Republican Party's past that could haunt it during this election, says Rachel Maddow.

Donald Trump has claimed that the election is "rigged" and has gone so far as to suggest that his followers volunteer to monitor the polls. But poll watching terrifies the Republican National Committee, Maddow noted on her MSNBC show Monday night, because the party was sued over racially targeted poll watching in New Jersey during the 1981 governor's race.

In that race, Maddow says, the party challenged the registration of thousands of voters in the state. In around 75 "minority-high" precincts across the state, Republicans patrolled neighborhoods and put up four-foot-tall signs that read, "Warning: This area is being patrolled by the national Ballot Security Task Force. It is a crime to falsify a ballot or to violate election laws."

The task force, created by the RNC, was a stealth operation that came seemingly out of nowhere, said Maddow. It included off-duty police officers and sheriff's deputies wearing "Ballot Security Task Force" armbands, and many of them were holding guns. The group "stalked around polling places in minority-heavy districts while they demanded that election workers strike these people off the voting rolls," said Maddow.

Her report plays clips from that era showing that Democrats believed the Republican Party was trying to suppress voting, not prevent fraud. Maddow says the plan for voter suppression on the part of the Republicans worked in their favor. The election that year was "decided by less than 1,800 votes," said Maddow. (The winner, incidentally, was Thomas Kean over Jim Florio.)

The Democratic Party sued the Republicans, and the lawyer who defended the Republicans was Donald Trump's brother-in-law, John J. Barry. The Republican Party was forced to sign a consent decree that expires in December of 2017. The decree prohibits the Republican Party from engaging in this type of behavior, such as "poll watching" that may target minority voters once again.

And now Trump has brought this issue up again, which could create long-lasting problems for the Republican Party. Though Trump is asking his supporters to monitor voters, the RNC has sent an email out asking party members not to follow Trump's instructions. If the party is caught violating the decree, it will extend until 2025.

Watch Maddow explain more about the task force below.