A bipartisan proposal that would tighten disclosure laws for groups that run political ads but aren't formally connected with candidates or parties seems to be zipping through the Legislature in recent days.

However, changes made in recent days to Senate Bill 11, recommended by the Attorney General's Office, have some nonprofit charities worried they will be burdened by the bill -- which is aimed at "super-PACs" that formed in the wake of the Supreme Court's "Citizens United" decision.

The bill, co-sponsored by Sen. Peter Wirth, D-Santa Fe, and Rep. Nate Gentry, R-Albuquerque, unanimously passed the Senate on Sunday. On Tuesday, the House gave a do-pass recommendation to the bill, which now is on the House floor calendar.

But before the Senate passed the bill, the Senate Judiciary Committee passed a substitute recommended by Attorney General Gary King's office that has caused, in Wirth's words, "heartburn" for some groups that supported the bill in its original form.

The substitute would require that any group, including a nonprofit, that sends "educational material" -- ads or mailers -- that mentions any political candidate has to disclose large donors if the material is sent within 58 days of a general or primary election.

Sandra Adondakis, lobbyist for the American Cancer Society Cancer Action Network, said the bill as it stands would be burdensome to her organization.

"We're a nonpartisan, middle-of-the road group, but we're a single-issue group -- cancer," Adondakis said Tuesday. She said her organization sometimes sends mail asking supporters to contact officials about specific cancer-related issues such as clean indoor air and breast and cervical cancer.

"During an election year, that would be four months out of the year we couldn't name a candidate without disclosing everyone from anywhere in the country who contributed more than $5,000," she said. To avoid that, Adondakis said, groups would have to set up separate bank accounts for New Mexico.

Steve Allen, of the state chapter of the American Civil Liberties Union, said Tuesday that his organization has major problems with requiring groups to register with the government when they want to speak out about how the government works and what politicians are doing.

Both Allen and Adondakis said they supported the original version of the bill. Last year Allen, then working for Common Cause New Mexico, helped to craft a similar bill sponsored by Wirth and Gentry. That 2011 bill passed the Senate but died before the full House heard it.

However, Stuart Bluestone of the Attorney General's Office, who helped draft the committee substitute, said Tuesday that he doesn't believe the current version of the bill infringes on any group's freedom of speech. "The bill doesn't prohibit anything," he said.

Bluestone said the changes were made partly in response to a 2008 situation in which Albuquerque-based nonprofit groups, including the Center for Civil Policy, sent mailers, shortly before the primary election, questioning the ethics of several legislators -- some of whom lost their re-election bids.

King took those groups to court that year, claiming the mailers in effect were political ads and the contributors should be disclosed. However, federal Judge Judith Herrera ruled against King and in favor of the nonprofits.

King's office and the nonprofits agreed to a compromise amendment that would have shortened the time before a primary in which mentions of candidates would trigger the law. However, the House Voters and Elections Committee voted against adopting the amendment.

Wirth said the amendment could be introduced when it gets to the House floor. But he added, "Whether it goes on or not, this bill is incredibly important so donors to these entities are disclosed and voters have information [about contributors to super-PACs and other groups working independent of campaigns] at the polls."

Contact Steve Terrell at 986-3037 or sterrell@sfnewmexican.com. Read his political blog at roundhouseroundup.com.