After his father paved the way for this practice by releasing 12 years of tax returns during his gubernatorial campaign (intended to show the voters that his wealth was not a fluke), Mr. Romney has released one (2011) and plans to release another (2010), but has refused to provide anything further -- allowing the Obama Campaign to easily paint whatever image of the candidate that they want. Obama has released every return since 2000.
Obviously, there are things in those returns that the campaign doesn't want to be made public, but it seems his long-term trade off in public trust and an inability to control the campaign narrative are not worth the avoidance of the short-term blows his campaign may get hit with. If the past is, indeed, prologue than the former Governor may not release them, even if it risks the election.
When do you think the candidate will release a large batch of returns?