Mikulski needs GOP votes to pass the measure through the Senate, which Democrats control with 55 votes but where 60 votes are required for virtually every piece of substantivelegislation.
Heated debate by committee members on Thursday showed the partisan divide over gun legislation, as well as the challenge supporters face in getting any substantive measures through Congress.
On climate change, the heavy negotiations for the United Nations and the EU have now become somewhat more publicly vocal in their criticism of the administration in their interpretation it's not working hard enough to bring climate change legislation and an agreement to Copenhagen, to have something that's substantive that can be a part of the overall negotiations.