But if Clinton is smart, she'll find a job in her Cabinet for Warren. And it's not just because Warren as veep could scare off moderate Republicans or dry up Wall Street donors. It's because, if Clinton wants to win, she'd be wise to make another choice. And, no, it's not Virginia Sen. Tim Kaine, the safest, least exciting choice — just look at the yawns that followed all the trial balloons this month.