The legislation contains a credit union-specific provision that provides that a one-to-four family dwelling that is not the primary residence of a member will not be considered a business loan under the Credit Union Act.

The bill also includes a provision that "provides that certain mortgage loans that are originated and retained in portfolio by an insured depository institution or an insured credit union with less than $10 billion in total consolidated assets will be deemed qualified mortgages under the Truth in Lending Act, while maintaining consumer protections," according to a summary of the bill.

The measure also would exempt depository institutions that have originated fewer than 500 open-end lines of credit and closed-end mortgages in the previous two years from certain HMDA reporting and recordkeeping requirements.

The bill also would increase the so-called "too big to fail" threshold from $50 billion in assets to $250 billion in assets and it is that provision that has gained the most opposition from consumer groups.

Credit union trade groups have been pressing the Senate to consider the bill on the floor.

"We're thankful to Senate leadership for carving out floor time for this important piece of bipartisan legislation," said CUNA President/CEO Jim Nussle. "Washington doesn't seem to agree on much these days, but the bipartisan support this bill has seen since its introduction shows that the need for relief goes above party politics."

In a letter to committee members as they debated the bill, NAFCU Executive Vice President of Government Affairs and General Counsel Carrie Hut called the measure "and excellent step toward providing bipartisan regulatory relief and economic growth."

However, Brown said the bill puts taxpayers at risk of bank bailouts by weakening the rules on some of the largest banks. In addition, he said, it weakens stress tests for regional and larger banks.

"I support providing some relief to small banks and credit unions, but I think this bill unwisely chooses to do so by rolling back protections for people from the very activities that led to the crisis," he said, as the committee debated the measure.  "Just as the nation's smallest banks didn't cause the crisis, neither did mortgage customers."

Americans for Financial Reform, a consumer group also opposes the bill, calling it "a bank lobbyist's dream: it contains over two dozen deregulatory gifts to the financial industry."

The Senate bill is a much more modest measure than House Financial Services Chairman Jeb Hensarling's (R-Texas) Financial CHOICE Act. That bill would make huge changes to Dodd-Frank and would reduce the power of the CFPB. The bill had no Democratic support in the Senate.

The Senate never intended to consider Hensarling's bill because it contains provisions that would be unlikely to be accepted by 60 members—the number of senators generally needed to pass controversial legislation.

And so even if the Senate passes Crapo's bill, it sets up a House-Senate conference with vastly different measures to be reconciled.