Story highlights Democrats have filed pre-emptive lawsuits against the GOP in Pennsylvania, Ohio and Nevada

(CNN) As Democrats warn their supporters of voter suppression efforts and Donald Trump urges his followers to watch polling areas, lawyers from both sides are filing fiery legal briefs and laying the groundwork for potential challenges on Election Day.

In states such as Ohio, Pennsylvania, Arizona and Nevada, lawyers for state Democratic parties are in federal court alleging that the Trump campaign and others are "conspiring to threaten, intimidate, and thereby prevent minority voters in urban neighborhoods from voting in the 2016 campaign."

They are asking for a temporary injunction to block "such conduct" through Election Day.

In legal briefs, they quote Trump from a speech last August. "I hope you people can...not just vote on the 8th, [but also] go around and look and watch other polling places and make sure that it's 100-percent fine," Trump told an audience in Pennsylvania.

"Immediate relief is necessary," Donald J. McTigue, a lawyer for the Ohio Democratic Party argued in court papers filed in the Ohio case. McTigue said that the defendants' including the Trump campaign, the Ohio Republican Party and Trump supporters are engaged in a "coordinated campaign of vigilante voter intimidation" and in violation of the Ku Klux Klan Act of 1871 and the Voting Rights Act of 1965.

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