This really, really annoys me. Why are these "centrist" Democrats so very enamored of allowing Republicans to filibuster? There's a reason why a majority of voters selected candidates with a "D" after their names - they didn't want any more Republican policies!

WASHINGTON -- President Barack Obama urged Democrats on Capitol Hill Wednesday to maintain party unity and preserve his fiscal priorities, as the House and Senate began moving on companion versions of a $3.6 trillion budget that would make good on his promise to cut the federal deficit in half.

Congressional leaders are sticking broadly to the priorities outlined by Mr. Obama in a budget message sent earlier this month to Capitol Hill. But important differences are emerging, as tensions simmer among Democrats over issues such as climate change and health care, as well as spending.

Notably, Democratic leaders in both chambers are pushing packages that call for narrower deficits and less spending than proposed by the White House. And those levels could go lower, especially in the Senate, where moderate Democrats from conservative states will be an important factor in the debate on the floor next week.

Democratic moderates are pressing for even further spending cuts, especially in domestic programs. Sen. Ben Nelson of Nebraska, one of those centrists, said more needs to be done to rein in spending. "This is a good direction, but I'd like to see it even lower," Mr. Nelson said.

Significantly, both the House and Senate decided to abandon a White House request for additional money for the Wall Street rescue. The two chambers also don't intend to invoke special legislative powers -- known as "reconciliation" -- that would allow climate-change legislation to avoid a filibuster in the Senate. That means any bill designed to control harmful emissions will have to attract 60 votes in the Senate, essentially ensuring any climate-change bill will require Republican support.