By all accounts, the Internet's first politically motivated mass work-stoppage on Wednesday was a rousing success, and so far 13 19 U.S. Senators have flipped their stance on pending anti-piracy legislation that critics say would severely harm the freedom of speech online.

But the real story is, all but two of them are Republicans. (Update, 1:20 p.m. EST: A third Democrat, Sen. Mark Begich (D-AK), came out against the anti-piracy legislation later Thursday morning, bringing the total number of Senators now opposed to 26. Only eight are Democrats.)

While Silicon Valley may have found their voice echos on Capitol Hill more loudly than expected, what remains after Wednesday's protest is even more telling that what provoked it: Senate Democrats are now the core pillars of support for the Protect Intellectual Property Act (PIPA), which has not otherwise engendered a strict partisan divide among lawmakers.

Far and away, the top beneficiary in the Senate from interest groups that support PIPA is Sen. Barbara Boxer (D-CA), who's taken in just short of a million dollars from those groups, according to data from She's also the most recent Senator to co-sponsor PIPA, adding her name to the list on Dec. 12. The runner-up is Sen. Al Franken (D-MN), who's taken $777,383 from PIPA-supporting interest groups, and has co-sponsored the bill since May 2011.

In fact, a list of the top 20 beneficiaries of special interest money in favor of PIPA reads like a list of the Senate's most influential Democrats: Sen. Kristen Gillibrand (D-NY) in third; Sen. Harry Reid (D-NV) in fourth; Sen. Chuck Schumer (D-NY) in fifth; Sen. Patrick Leahy (D-VT), the bill's primary sponsor, in sixth; Sen. Dianne Feinstein (D-CA) in seventh; Sen. Claire McCaskill (D-MO) in eighth; Sen. Sheldon Whitehouse (D-RI) in ninth; and Sen. Michael Bennet (D-CO) in tenth.

The list goes on like that until Sen. Mitch McConnell (R-KY), who places 15th with $274,600 in special interest money promoting PIPA. He has not yet announced an official position on the bill. The only other Republican on the list of the top 20 PIPA beneficiaries in the Senate is Sen. Bob Corker (R-TN), in 19th place with $212,312. Corker is one of the bill's co-sponsors.

In total, only two Democrats changed their minds on PIPA during Wednesday's blackouts: Sens. Ben Cardin (D-MD) and Jeff Merkley (D-OR). The other 11 to walk away were all Republicans, who seem more open to Silicon Valley's warnings against onerous, job-killing regulations.

That may be due to the total sum donated to Democrats on the top 20 list: groups supporting PIPA have given over $7,319,983 to the 18 Democrats on the top 20 list, according to a Raw Story analysis. By contrast, those same Democrats have only taken in $807,502 from groups opposing the legislation.

It could also be attributed to a smart hire by the Motion Picture Association of America (MPAA), the primary industry group behind the anti-piracy bills, which snapped up former Sen. Chris Dodd (D-CT) to be their chief lobbyist. Amid Wednesday's online blackouts, Dodd issued a statement condemning the protest as a "dangerous gimmick," and chastised Internet companies for abusing their freedoms in the marketplace.

As yesterday's strike wore on, Raw Story reached out to all the leading Democratic senators supporting PIPA, in hopes they would step up to defend the bill. Not a single one did, and none of Raw Story's requests for comments defending PIPA received responses.

Google reported that over 4 million people signed their anti-piracy petition on Wednesday, and technology advocacy group The Electronic Frontier Foundation (EFF) told Raw Story that over 350,000 people used their website to communicate their displeasure to Congress, sending more than 1 million letters.

"I hope to see more Democrats turn around on this," said Parker Higgins, an activist with the EFF who's focused on the anti-piracy bills. "I don't know if it's a question of party politics or whether there's still something they see in the bill that we don't think there should be. We're hoping that in the next couple of days they'll wake up to this. It's not a good thing to be supporting."

The Obama administration said recently that it was hedging its bets on the anti-piracy bills as well, saying on Saturday that any anti-piracy legislation passed by Congress must balance concerns about censorship with the need to enforce intellectual property rights. The White House said they hope such a balance would "avoid creating new cybersecurity risks or disrupting the underlying architecture of the Internet."

Senate Majority Leader Harry Reid said on Sunday during an appearance on NBC's Meet the Press that he would move forward with a full Senate vote on PIPA in the coming weeks, once some of the text had been altered to build consensus on the legislation.

It is not yet clear if it will pass, but that may not even matter because in the House, PIPA's sister-bill the Stop Online Piracy Act (SOPA) is now stalled indefinitely. Majority Leader Eric Cantor (R-VA) has said he will not bring it to a vote until there's wide bipartisan agreement, and fellow influential Republicans Rep. Paul Ryan (R-WI) and Rep. Darrell Issa (R-CA) have insisted they will go to the mat to block the bill in its current form.

Because of the House-Senate divergence on both bills, it looks like the anti-piracy legislation is impossibly stalled for the time being unless significant changes somehow break the logjam.

In the first major battle over U.S. Internet policy, Silicon Valley appears to have won -- but the war has only just begun. Another day of action against PIPA was planned for Jan. 23, one day before Senators are expected to vote on the bill.

(Disclosure: Raw Story Media, Inc. was one of the companies that blacked-out on Wednesday after the site's owner and publisher determined the bills pose a threat to continued business operations.)

Photo: Flickr user JRockefellerIV.