WASHINGTON - A senior Democratic lawmaker said Sunday he had "no doubt" that Russia was behind recent hacking attempts targeting state election systems, and urged the Obama administration to publicly blame Moscow for trying to undermine confidence in the Nov. 8 presidential contest.The remarks from Representative Adam Schiff, the top Democrat on the intelligence committee in the US House of Representatives, come amid heightened concerns among US and state officials about the security of voting machines and databases, and unsubstantiated allegations from Republican candidate Donald Trump that the election could be "rigged.""I have no doubt [this is Russia]. And I don't think the administration has any doubt," Schiff said during an appearance on ABC's "This Week."Schiff's call to name and shame the Kremlin came a week after Trump questioned widely held conclusions made privately by the US intelligence community that Russia is responsible for the hacking activity."It could be Russia, but it could also be China," Trump said during a televised debate with Democratic candidate Hillary Clinton. "It also could be somebody sitting on their bed that weighs 400 pounds."