Job: Chairman of the New Hampshire Democratic Party
What He Said About Romney: "I challenge him to release additional tax years of tax returns, or the public will never know if he created a shell corporation to avoid taxes."
Tax Status: Not released
Buckley's press secretary, Collin Gately, said presidential candidates should disclose "what conflicts of interest may exist." But he said "the same potential conflicts do not exist with a state party chair."
"Unlike Mitt Romney, Chairman Buckley is not running for President," Gately said in a statement. "Chairman Buckley hasn't released his tax returns but he promises to do so if and when he is a candidate for President of the United States like all candidates in the last 30 years with the exception of Mitt Romney."
Job: Chairman of the Colorado Democratic Party
What He Said About Romney: "The American people deserve to know if a man who wants to be president was investing in offshore bank accounts to avoid paying taxes here at home."
Tax Status: Some released, some not released
Palacio released his financial disclosure forms for the five years that he was a congressional staff member, as required. He hasn't released his tax returns since.
"I don't think that there's anyone that has any interest in looking at my tax returns," Palacio said. "I'm a state party chair. I'm not a guy running to be the most powerful person on the planet. It's entirely not even in the same ballgame -- we're not even on the same continent here for comparative purposes."
Job: Governor of Maryland
What He Said About Romney: "He bet against America when he put his money in Swiss bank accounts and tax havens and shelters and also set up a secret company, the shell company in Bermuda, which, by the way, in order to avoid disclosure, he put in his wife's name right before he became governor of Massachusetts."
Tax Status: Released
As part of his campaign for governor, O'Malley and his opponent released their tax returns. They showed that he and his wife were on track to make $1.2 million during his four-year term.
Job: Mayor of Aspen
What He Said About Romney: "That Mitt Romney won't talk about that offshore money -- where it is and how much it is -- is pretty telling."
Tax Status: Not released
Ireland told ABC News that his tax returns have never been an issue, and he offered to release them. After finding them, he did -- five years' worth, from 2007 through 2011. They're available here.