REUTERS/Cheney Orr/File PhotoWASHINGTON, Oct 26 (Reuters) - Two in five U.S. voters say they are worried about threats of violence or voter intimidation at polling stations during the country's midterm elections, according to a new Reuters/Ipsos poll. But officials in Arizona, a key battleground, have already asked the federal government to probe a case of possible voter intimidation, after people casting ballots were conspicuously filmed and followed. Kathy Boockvar, a former top election official for Pennsylvania, said fears of voter intimidation and violence run counter to American tradition. Among the registered voters polled by Reuters/Ipsos, 43% were concerned about threats of violence or voter intimidation while voting in person. About two-thirds of Republicans and one-third of Democrats think voter fraud is a widespread problem, the Reuters/Ipsos poll found.

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