The prospects for congressional approval of climate change legislation this year have dimmed but not disappeared. Yesterday the Senate voted against using the filibuster-proof reconciliation process to consider climate change legislation by a 67-31 vote and the House-approved budget did not include cap-and-trade in its budget reconciliation provisions.

That makes it more likely that cap-and-trade legislation, now being drafted by Rep. Henry Waxman (D-Calif.), will have to win 60 votes in the Senate to become law. With Democratic qualms mounting (see Aaron’s post yesterday on Majority Leader Harry Reid’s meeting with coal state senators) and potential Republican supporters hanging back, 60 votes seems to be a tall order.

But cap-and-trade advocates are not deterred, notes The Washington Post today, with this significant aside: “Administration officials support leaving the door open in the budget blueprint when it emerges from conference committee for a final vote this month.”

President Obama might still ask congressional leaders to take the more partisan route to get climate change legislation passed this year. Keeping the threat of reconciliation on the table has its uses. It was only after Office of Management and Budget director Peter Orszag’s threat of reconciliation that GOP Sens. John McCain (R-Ariz.) and Lindsey Graham (R-S.C.) reiterated their support for cap and trade. Sen. Benjamin Cardin (D-Md.) told the Post “a lot of us don’t want to give up without a fight.” Reconciliation remains a weapon in that fight.