The Senate early Tuesday morning overwhelmingly approved a compromise measure averting the "fiscal cliff," sending the bill over to the House, which is likely to act when it convenes at noon.

The rare New Year's Day vote on the measure -- which passed the Senate 89-to-8 -- came hours after the country officially plunged over the cliff at midnight.

Senate leaders had been waiting to schedule the vote until they had received an official score from the Congressional Budget Office, which provides estimates for the budgetary impact of legislation.

But even though that score was released before the measure was voted upon, it's unlikely that many senators had the chance to read the entire 157-page bill before casting their votes early Tuesday morning.

Support for -- as well as opposition to -- the compromise spanned the ideological spectrum. The eight senators voting "no" were Democratic Sens. Tom Harkin (Iowa), Tom Carper (Del.), Michael Bennet (Colo.) and Republican Sens. Mike Lee (Utah), Richard Shelby (Ala.), Rand Paul (Ky.), Chuck Grassley (Iowa) and potential 2016 White House hopeful Marco Rubio (Fla.).

Rubio's "no" vote could put pressure on House Budget Committee Chairman Paul Ryan (R-Wis.), another potential 2016 hopeful. Ryan has previously voted "yes" along with members of House leadership, but that could change in the face of a heated presidential primary fight.

House Speaker John Boehner (R-Ohio) has pledged that the House will vote on any Senate-passed deal. But late Monday, in a joint statement with other House GOP leaders, he made no assurances that the chamber would pass such an agreement as-is, leaving open the possibility of amending the measure and thus even further prolonging the fiscal cliff negotiations.