Republican Sen. Charles Grassley (R., Iowa) crossed the aisle today, and voted with all 12 Democrats on the Senate Agriculture Committee to send sweeping new derivatives regulation to the Senate floor, where it will be merged with the Dodd bill as part of the Democrats’ far-ranging effort to reshape Wall Street.

Grassley breaking-of-rank is the latest in a series of signs that Senate Republicans are softening their tone on the Democrats’ financial reform bill, and that Democrats, for their part, seem willing to negotiate.

The change in tone was reflected in remarks by Senate Minority Leader Mitch McConnell (R., Ky.), who said he was “heartened to hear that bipartisan talks have resumed in earnest,” and later told reporters he is “convinced now there is a new element of seriousness attached to” negotiations to iron out differences in the bill.

In a similar vein, Sen. Richard Shelby (R., Ala.), ranking Republican on the Senate Banking Committee, said “I believe we’re going to get us a bipartisan bill,” and intimated that negotiations had moved beyond broad principles and were “down to words and phrases.”

At least one Democratic Senator came out in favor of yielding to Republicans on areas of disagreement in order to move the bill forward.

“At the end of the day…we agree on about 80 percent of the stuff here,” said Sen. Tom Carper (D., Del.) during an appearance on Fox News. “I think what we need to do is focus on the 80 percent on which we agree and set aside the 20 percent for another day.”