The arcane rules of the chamber provide the minority party significant power to stall. If Republicans use all the delay tactics available to them the Senate may not complete the continuing resolution until Sunday, Democratic leaders and aides say. That would send the bill back to the House less than two days before a shutdown.
The House passed a continuing resolution (CR) on Friday that strips funding to implement Obamacare. Senate Democrats intend to restore that funding. But in the process of passing their version, they'll have to jump through procedural hoops and grant GOP senators opportunities for hours upon hours of delay, which conservative senators who insist on keeping the Obamacare funding have incentive to use.
In procedural terms, Rule 22 of the Senate guarantees 30 hours of debate after cloture, and several cloture motions are required. Republicans are unlikely to yield their time because ultraconservatives, led by Sen. Ted Cruz (R-TX), have committed to using every tactic at their disposal to gum up the works unless Democrats fold on Obamacare.
One reason Democratic leaders hope to get consent is many Republican senators want to avoid a shutdown and are on record opposing conservatives' strategy to use the must-pass continuing resolution as leverage to defund the health care reform law.
If they don't get consent, here's what Senate Democratic leaders currently plan on doing: they'll file cloture on the motion to proceed to the House's continuing resolution. The vote on the motion to proceed probably comes Wednesday, which will mean 30 hours of debate before they can proceed. It won't be until Friday when they can bring up a "motion to strike" the language defunding Obamacare (which Senate Majority Leader Harry Reid (D-NV) intends to do at a 51-vote threshold). And then another motion before they can proceed to final passage. That brings the Senate into Sunday before they can wrap it up.
The timing would put pressure on Speaker John Boehner (R-OH) to bring up the Senate legislation, given the GOP's virtually impossible odds of actually defunding Obamacare, lest he risk being blamed for the first government shutdown since 1996. Such a move would anger many House Republicans, but the bill could pass with Democratic votes.