The New Hampshire Union Leader said that Romney position "creates the impression, justly or not, that there is something there to hide."
"Those voters might not cast their ballots for Obama, but not voting can be just as damaging. And yes, for using the tax dodges and loopholes legally available to him, he might lose votes as well."
The editorials from conservative papers came as other outlets dug into the business dealings of Bain Capital. One report described "pioneers in the practice of shipping work from the United States to overseas" companies.
Another accused him of being "willing to push into gray areas when it came to business."
These reports made their way into Democratic ads, while Romney's campaign generally objected to and pushed back against the reports.
Then, Democrats stepped forward with an offer.
"If the Governor will release five years of returns, I commit in turn that we will not criticize him for not releasing more-neither in ads nor in other public communications or commentary for the rest of the campaign," Obama campaign manager Jim Messina wrote in a letter to Romney's campaign manager.
The Romney campaign's response: Thanks, but no thanks.
"It is clear that President Obama wants nothing more than to talk about Governor Romney's tax returns instead of the issues that matter to voters, like putting Americans back to work, fixing the economy and reining in spending," wrote Romney campaign manager Matt Rhoades in reply.
An anonymous group said earlier in September that it had obtained copies of prior Romney tax returns and threatened to release them should a ransom not be paid by September 28, next Friday.
Romney's financial firm, PricewaterhouseCoopers, said it was cooperating with the Secret Service but added "there is no evidence of unauthorized access to our data."
While the Friday release seems unlikely to put to rest Democratic criticism of Romney's finances, surrogates for the GOP candidate said in statements released by the campaign that it was time to move on.
"Mitt Romney has now released more than 1,200 pages of tax returns, giving voters an incredibly detailed look at his finances," Sen. John McCain said.
"Now that the most recent tax return has been released, it's time to get back to discussing the issues that voters care about. While President Obama and Democrats will try to distract voters, Mitt Romney and Paul Ryan are focused on fixing the economy, getting Americans back to work and ensuring a better future for our children and grandchildren."