A Washington lobbying shop filed a $1 million defamation suit Friday against the Democratic Party of Virginia and a legislative candidate over an ad that links the firm to the abuses at the Abu Ghraib prison in Iraq. The Livingston Group, founded by former U.S. Rep. Bob Livingston, is asking a Fairfax County court to rule on the accuracy of a mail ad that Democrat Rex Simmons used to attack Del. Tim Hugo, R-Herndon. Hugo is a part-time lobbyist with the firm. The Democratic Party of Virginia paid for the ad, but Simmons’ campaign approved it. The ad in question...