Washington (CNN) - The growing Internet protest–including a planned blackout by some websites Wednesday– against an online anti-piracy bill moving through Congress is "daunting," a Senate Democratic aide said Tuesday.
The aide said the protest may be powerful enough to keep senators from voting to even take up the bill that until recently commanded rare bipartisan support.
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"Before it looked like it would pass with 80 votes, and now [the online protest] looks like something that will suck the votes away," the aide said. "We're at a tipping point. It will either become a huge issue or die down a bit and that will determine the future of this."
The aide said it was premature to say exactly how it will play out but acknowledged that because of protest from Internet mainstays like Google and Wikipedia "the merits of the bill are getting lost" and "sand is shifting pretty quickly" against it.
Senate Judiciary Chairman Patrick Leahy, D-VT, is weighing changes to the bill to address concerns in the online community. In particular, he is considering dropping a provision that would impose new requirements on Internet service providers.
Senate Democratic leaders scheduled the bill as the first order of business when the Senate returns to work next week. They considered it one key part of their overall job creation agenda.
Senate Majority Leader Harry Reid said he was open to changes to satisfy critics.
In a letter last week to GOP senators concerned about the bill, Reid acknowledged the bill "is not perfect" but said it would "protect American ingenuity and commerce" and is "too important to delay."
"It's tough to believe that after another week of this we're going to be able to get cloture [the 60 votes needed to take up the bill], so that would settle it for the immediate term," the Senate Democratic aide said.
Texas Republican Congressman Lamar Smith, who is leading the effort to move a bill in the House, criticized efforts by the bill's opponents to mount the blackout on Wednesday.
"This publicity stunt does a disservice to its users by promoting fear instead of facts," Smith said in written statement Tuesday.
Smith has already agreed to make changes to his legislation in response to concerns by opponents. His statement stressed that the House bill "only targets foreign websites that are primarily dedicated to illegal activity. It does not grant the Justice Department the authority to seek a court order to shut down any website operated in the U.S."
California Rep. Darrell Issa, who is pushing his own legislation as chairman of the House Oversight Committee, cancelled a hearing scheduled Wednesday on the problems that Google and others have with the bill.
But in a statement Friday, Issa said, "Majority Leader Cantor has assured me that we will continue to work to address outstanding concerns and work to build consensus prior to any anti-piracy legislation coming before the House for a vote."
Despite signals from House GOP leaders that the bill won't be scheduled for a vote until some of the controversial provisions are worked out, Smith announced that his committee plans to consider the bill early next month.
Time Warner, the parent company of CNN, is among the industry supporters of the legislation.