The most devastating political ad. Ever.

This is the only political ad I've ever seen that has actually made tears well up in my eyes. Michael J. Fox is a person I grew up with, in a sense: Family Ties, Back to the Future, Spin City... On Family Ties he played the conservative son of liberal ex-hippies. He has always conveyed a persona of being reasonable, measured, and an all-around decent human being.

Seeing him in such a degenerated condition is a shock. Seeing him retaining his dignity while pleading for his life is a sight that can hardly fail to move all but the most absolutist I'm-anti-stem-cell-research-because-all-life-begins-at-conception crowd. This ad makes the political extremely personal. It speaks directly to voters, saying that your vote matters because it matters to people you care about.

This could be the ad that flips the Senate. It should.