WASHINGTON -- The Senate on Tuesday voted in favor of a measure, 67-29, that would allow Americans to carry firearms in national parks, if their state laws permit them to possess a gun, with 27 Democrats voting in support.

But because the measure was passed as an amendment to a broader bill seeking reform of the credit card industry, the move jeopardizes the reform bill, whose lead sponsor, Sen. Chris Dodd, opposed the firearm amendment.

The amendment was sponsored by Sen. Tom Coburn, R-Okla., who has been fighting for some time for the measure. Dodd, a Connecticut Democrat, voted against the Coburn amendment.

Dodd voiced concern that, as amended, his credit card reform bill could meet the same fate as the D.C. voting rights bill, which was sidelined in the House when it was amended to allow residents of the District of Columbia to carry guns.

The Coburn amendment to the credit card bill would allow states to determine whether or not legal gun owners can carry guns in state and national parks. It prohibits the Department of Interior secretary from making any rule or enforcing any regulation that goes against that determination.

Coburn cited statistics, including 41 rapes, 92 robberies, 16 kidnappings and 5,944 other felony violations taking place in national parks last year.

"Even though parks are relatively safe, oftentimes the best deterrent is for criminals to know someone else might also have a gun," Coburn said.

Sen. Jim Webb, D-Va., who became a nationally-known gun owner after an aide was detained for inadvertently carrying the senator's gun into a Capitol office building, spoke in favor of the amendment.

"It doesn't mean you can go hunting. It doesn't mean a 12-year-old can carry a gun" into a park, he said, adding that current law leaves means there is a risk of arrest for gun carriers who simply travel down a highway that might skirt or cut through a park, as happens in Virginia and other states.

No Democrat has spoken against the broader credit card reform bill. Senate Majority Leader Harry Reid of Nevada voted in favor of the amendment, though he warned senators afterward not to introduce any more unrelated amendments to the credit card legislation. Seven of the supportive Democrats are up for re-election in 2010, including Reid.

Dodd said it is possible, if the bill passes the Senate with the Coburn amendment, it still could be dropped in negotiations with the House over the different versions of the legislation.