I don't even know what that means any more. Left by contemporary American standards? Tea Party standards? Left by the American standards of, say, the 70s, when substantial numbers of Republicans supported a guaranteed income, the ERA, and federally subsidized child care? Left by the Republican standards of the 90s, when Republicans supported a health care plan that mandated universal compliance as their alternative to Hillarycare? Left by the standards of the world's industrialized nations? Or just left by the standards set up by the corporate media after 45 years of browbeating by the bought-and-paid-for mouthpieces of the superrich?
I don't know what "leaning left" means in contemporary America, but I'm pretty sure that taking exception to the current direction of the Republican party doesn't require much ideological fervor.