By Andy Sullivan
WASHINGTON (Reuters) - A U.S. judge in Ohio ordered Republican presidential candidate Donald Trump's campaign on Friday not to intimidate voters, in a victory for Democrats who sought to prevent Election Day harassment in one of the nation's most politically competitive states.
The order also deals a blow to a Trump-allied "exit poll" that aims to mobilize supporters to ask voters whether they had cast a ballot for the Republican real-estate mogul or Democrat Hillary Clinton.
On the campaign trail, Trump has said the election will be "rigged." He has called on supporters to keep an eye on voting activity for possible signs of fraud in large cities.
Democrats have said that could encourage Trump supporters to harass minority voters and have launched a legal blitz in six states to prevent that from happening.
Numerous studies have found that U.S. voter fraud is exceedingly rare.
Democrats declared the judge's decision a victory, saying it would prevent Trump supporters from interfering with voters in one of the most competitive U.S. states during the Nov. 8 election.
"We're pleased that the judge announced he will be issuing an order to prevent any harassment of voters along the lines that have been suggested by the Trump campaign," Ohio Democratic Party Chairman David Pepper said in a prepared statement.
The ruling does not prevent the state Republican Party from sending trained volunteers into polling places to make sure election laws are being followed.
However, it does apply to Trump supporters who may take it on themselves to monitor voting activity independent of the party. It prevents them from verbally harassing voters near polling stations, or taking pictures of them.
The ruling also applies to groups supporting Clinton's presidential bid.
It also shuts down an exit poll organized by Trump ally Roger Stone, who said he aims to uncover examples of vote manipulation. Stone told Reuters on Monday that participants are trained not to harass voters. Some 118 people in Ohio have signed up to participate through a web site called Stop the Steal. Stone did not immediately respond to a request for comment.
Ohio Republicans and the Trump campaign did not immediately respond to requests for comment.
(Editing by Kevin Drawbaugh and Andrew Hay)