The Democratic leadership and rank-and-file members are planning to prevent the chamber from conducting routine business, including allowing committees to meet for extended hearings when the Senate is in session. And they will demand an open process to consider health care when the Senate reconvenes Monday.

Democrats might use parliamentary maneuvers to prevent committees from meeting for longer than two hours.

If carried through, the hardball tactics would make it difficult for Republicans to schedule votes even on uncontroversial bills and nominees, further slowing down the already slow-moving body.

One Democratic source cautioned that the caucus may not go that far given the bipartisan atmosphere following the shooting at a congressional baseball practice Wednesday.

But other Democrats said they wanted to escalate the fight to give more prominence to the GOP's closed-door process of drafting health care legislation, which Republican leaders want to pass by month's end.

"As of yesterday, no decisions had been made about procedural tactics, but the message was that everything is on the table," a Democratic aide said.

A spokesman for Senate Minority Leader Chuck Schumer declined to comment.

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Senate Democrats weigh blockade to protest GOP health care plan - CNN