Mitt Romney announced yesterday that he would not release copies of his tax returns if he is the Republican presidential nominee, breaking with a long tradition in both parties.

• Huffington Post, Mitt Romney Declines to Release Tax Returns, Cementing Posture of Secrecy
• New York Times, Romney Says He Won’t Release Tax Returns
• Politico, Here We Go Again, Tax Return Edition

(Hat Tip: Francine Lipman, Ann Murphy.)

Update: William Jacobson (Cornell), This Will Not Stand – Romney Refuses to Release Tax Returns:

Just what we don’t need is a months long battle over whether a nominee will release tax returns, which simply will give Democrats another excuse to play class warfare.

By contrast, Newt pledged to release his tax returns if he becomes the nominee, and I presume all the other candidates would do so as well.

It’s a no win situation. If Romney doesn’t release the returns, the issue will dominate the general election media narrative. If he does release the returns under pressure, he will look weak and like a flip-flopper.