HAMPTON, Ill. - Democratic presidential candidate Hillary Clinton on Monday expressed concern about "credible reports" of Russian interference in the U.S. election and accused Donald Trump of being fixated on dictators including Russia's Vladimir Putin.Taking questions from reporters for more than 20 minutes on her campaign plane, Clinton said both Democrats and Republicans should be concerned about Russia's behavior."The fact that our intelligence professionals are now studying this and taking it seriously raises some grave questions about potential Russian interference with our electoral process," Clinton said."We are facing a very serious concern. We've never had a foreign adversarial power be already involved in our electoral process. ... We've never had the nominee of one of our major parties urging the Russians to hack more," she said.