Senate Minority Leader Mitch McConnell (R-Ky.) warned senators Monday to oppose the growing momentum for dramatic reform of the filibuster, saying, "It may be the most important thing you ever do." Use of the filibuster to stall legislation -- when the minority party refuses to end debate on a bill unless 60 senators vote to do so -- has escalated in recent years, rising from a rarity to the norm. Senate Majority Leader Harry Reid (D-Nev.) has been signaling his readiness to curb the tactic, often noting that he has faced 385 filibusters during his leadership while Lyndon Johnson had to deal with only one when he ran the Senate.