Arthur J. Finkelstein, a longtime GOP pollster and strategist credited with helping elect Presidents Richard Nixon and Ronald Reagan, has died at age 72 of lung cancer, his family says.Finkelstein, considered less flamboyant but arguably more influential than better known Republican strategists, such as Lee Atwater and Roger Ailes, is widely regarded as the man responsible for turning the word "liberal" into a pejorative to be wielded against Democrats. He was also considered a pioneer in developing political action committees to raise vast sums of money for campaigns."Those who matter in politics are familiar with Arthur, but no one beyond that; which is the way Arthur likes it," wrote Craig Shirley at National Review in January. "He's never been the face of a wristwatch, but the gears would not run without him. While other consultants run to the spotlight, Arthur has always run away from it."He was instrumental in helping to elect or re-elect such figures as Sen. Orrin Hatch of Utah, North Carolina Sen. Jesse Helms, Sen. Strom Thurmond of South Carolina, New York Sen. Alfonse D'Amato and New York Gov. George Pataki. He also worked on campaigns for Israeli prime ministers Benjamin Netanyahu and Ariel Sharon.Minnesota Democratic Sen. Paul Wellstone told The Washington Post in 1996 that Finkelstein "dictated the message strategy" for Republicans, which was to charge "liberal, liberal, liberal."According to The New York Times, Finkelstein "pioneered sophisticated demographic analyses of primary voters and methodical exit polling, and of using a marketing strategy, called microtargeting, to identify specific groups of potential supporters of a candidate regardless of their party affiliation."