From the Q&A with Barney Frank in yesterday's NYT Magazine:

You’ve long argued for the decriminalization of marijuana. Do you smoke weed?

No.

Why not?

Why do you ask a question, then act surprised when I give an answer? Do you think I lie to people?

I thought you might explain why you support decriminalizing it but don’t smoke it.

Do you think I’ve ever had an abortion?

Go read the whole thing.