On Morning Joe today, Chris Christie made the pitch.
"The way I've conducted myself in my public life all along is I've released all my tax returns, and I did it during the campaign -- went back a number of years and released my tax returns, and I've released them every year right after I filed them to the public in New Jersey so they can see everything.
And I think that's the right way to go, and that's what I would tell Governor Romney to do. Now he says he's going to release them in April. I hope he does.
The fact of that matter is that's what I would advise him to do."
Christie has been one of Romney's more vocal and important surrogates (with apologies to John Sununu), and Team Mitt probably isn't too happy that he's joined the chorus on the tax returns.