Thursday night the Senate passed the most robust financial regulation bill since the Great Depression. The legislation, authored by Banking Committee Chairman Christopher Dodd (D-CT), passed mostly along party-lines, 59 to 39. Four Republicans voted in favor; two Democrats voted in opposition; and two Democrats abstained. The bill will now have to be reconciled through the conference process with the mostly less aggressive House's bill passed in December.

The Republicans could have delayed the final vote for 30 hours after the cloture motion passed on Thursday afternoon, but declined to do so. Without any hope of derailing the bill, there really would have been no point in a delay.

There were a few amendments that were supposed to be voted on before the final vote, however. The first was sponsored by Sen. Brownback (R-KS) and would have excluded auto dealers from the consumer financial protection bureau's jurisdiction. But Republicans declined to bring up the amendment, as not forcing a vote automatically killed another amendment that they were against -- one sponsored by Senators Merkely (D-OR) and Levin (D-MI) that would have banned banks from proprietary trading. Republicans are likely hoping that they get their amendment through the conference process, however, since the House bill excludes auto dealers from the new consumer protection regulator.

As for the final tally, the four Republicans Senators voting in favor included Olympia Snow (ME), Susan Collins (ME), Scott Brown (MA), and Charles Grassley (IA). The only surprise there was Grassley, who did not side with Democrats on the cloture vote. The two Democratic Senators who voted against the bill were Russ Feingold (WI) and Maria Cantwell (WA). Their vote reflected their disapproval that additional more aggressive amendments were not given a vote before final passage. Senators Arlen Specter (D-PA) and Robert Byrd (D-WV) did not vote.

The House and Senate bills have many similarities; in fact, it's probably not a stretch to say that they are both built on the same foundational ideas. They each create a new systemic risk regulator, non-bank resolution authority, consumer watchdog, and a more aggressive regulatory framework for derivatives and securitization. But there are also some very important differences between the two bills, as the Senate bill is more aggressive in some ways, like on rating agencies and derivatives. But the House's bill contains tougher language in other sections, such as setting leverage limits and creating a truly independent consumer financial protection agency.

In the weeks to come, the two chambers will have to compromise on a final version of the bill. Then it will make its way to President Obama's desk, who will eagerly sign it into law. Given the sense of urgency among Democrats to wrap the bill up, we should see the President sign it this summer.