Washington ? Senate Republicans are using the filibuster to limit and often derail Democrats’ initiatives, paralyzing the Senate and making it nearly impossible to accomplish even the most routine matters.

The filibuster strategy “makes the Senate dysfunctional,” said Mark Strand, the president of the Congressional Institute, a nonpartisan research group. That, in turn, blocks the Obama administration’s agenda, but it also sours public opinion on Washington, with polls showing clear public disdain for Congress in particular. Republicans think voters will reward them for that in November.

However disruptive it is to governance, their extensive use of the filibuster — extended debate to block a decisive vote — could prove to be a valuable campaign asset this fall. Democrats used similar tactics in 2006 and won enough seats to gain a Senate majority. Now Republicans hope it’s their turn.

Since Barack Obama became president nearly 13 months ago, Republicans have made it clear that 60 votes — the number needed to cut off debate in the 100-member Senate — are required to pass not only major Democratic programs, but also many routine proposals. (Democrats controlled 60 Senate seats from July until Feb. 4, when Sen. Scott Brown, R-Mass., was sworn in.)

“Republicans have ratcheted use of the filibuster up to completely unheard of levels. Look at the things that the House (of Representatives) has passed that can’t make it through the Senate. The list just keeps growing,” said Norman Ornstein, an expert on Congress at the American Enterprise Institute, a center-right policy organization.

The list includes legislation to overhaul health care, which has stalled and isn’t a good bet to be revived; global warming legislation; and a bill to overhaul financial regulation. Thursday, Senate Majority Leader Harry Reid of Nevada scaled back a bipartisan jobs bill, fearing that a larger package would get tied up in a filibuster. He also filed a “cloture petition,” meaning he plans a vote to cut off a filibuster if one starts.

The Senate’s 2009-10 votes to cut off filibusters have come on a wide variety of issues, big and small: Health care, domestic and defense spending, and 15 Obama nominees. While 38 of the 42 votes to cut off debate were successful, the debates about debates tie up the Senate and often prevent measures from ever reaching the floor.

“Republicans are gambling they can convince the American people Democrats can’t get much done, and at the moment, their gamble is paying off,” said former Sen. Bob Kerrey, a Nebraska Democrat and the president of the New School in New York.

During the 2005-06 session of Congress, Democrats ramped up use of the filibuster. The party controlled 45 seats and sensed the tactic could spur political gains in 2006. Democrats threatened or used filibusters on a wide variety of issues, including legislation affecting campaign finance, abortion, war spending, the Patriot Act, and the nominations of Samuel Alito to the Supreme Court and Dirk Kempthorne as Interior Secretary.

Democrats gained six Senate seats in 2006, capturing the majority, and for the next two years the unified, energized party used the tactic to defy increasingly unpopular President George W. Bush. The Senate took a record 112 votes to cut off debate in the 2007-08 session, about 18 percent of all Senate votes.

The current Congress is on a somewhat slower pace; so far, the 42 votes are about 10 percent of the total. While Democrats insist that Republicans are being obstructionist, GOP senators have a different view.

“It strikes me that Democrats are looking for someone to blame for their failed agenda that they can’t even get Democrats, let alone the American people, to support,” said Sen. Orrin Hatch, R-Utah, a 33-year Senate veteran.

Clearly, however, Republicans think they’ll gain politically at the polls, hoping that an annoyed public will punish those in power — Democrats — in this year’s midterm elections.

“Being unable to stop filibusters can make the party in power look ineffective,” said Julian Zelizer, a professor of history and public affairs at Princeton University, who’s written extensively on the filibuster. “The Republican goal now is to make Obama look like an ineffective leader.”