ABC’s Z. Byron Wolf reports: The latest sign of bipartisanship on the Wall Street reform bill is actual bipartisanship. Sen. Charles Grassley became the first Republican to support a piece of the Wall Street reform bill today. He in the Agriculture Committee today to report out the derivatives piece, which would regulate credit default swaps and force big banks out of the default swap business. A lot has happened since Senate Republicans pledged en masse last week to filibuster Democrats’ Wall Street reform bill. Grassley’s vote moves the process beyond the chummy atmosphere on the Senate floor and Senate Minority Leader Mitch McConnell’s conciliatory tone into the realm of on-the-record support for one part of the plan. The derivatives portion is only one piece of the reform puzzle. But Democrats will crow about this vote. Here is a Grassley paper statement, in which he refers to the Lincoln derivatives bill as “not bipartisan” despite his vote. “Even so, I voted for the Chairman’s derivatives bill today because I think transparency is the right policy,” said Grassley And his caveat on the larger reform bill, which he says does not yet have his vote: “My vote for this important reform of the derivatives market doesn’t mean I’ll be able to support the larger financial reform bill on the Senate floor. The derivatives piece is significant, but that larger bill has a number of flaws that need to be resolved before I’d support it. Again, I hope the majority leadership of the Senate allows the kind of debate, negotiation and amendment process needed to make those kinds of changes so that representative government can work as it should.” Grassley, it should be noted, was one of the Republicans that Democrats delayed their health reform bill in order to woo last year. But while Grassley turned against health reform in August, he’s obviously still very much at the Wall Street reform table.