Dems looking to slim down big banks

The measure mirrors a bill Miller introduced in 2010, and is a companion measure to one unveiled Wednesday by Sen. Sherrod BrownSherrod Campbell BrownHistory argues for Democratic Senate gains On The Money: Trump 'ready' for tariffs on all 0B in Chinese goods | Trump digs in on Fed criticism | Lawmakers drop plans to challenge Trump ZTE deal Dems pressure GOP to take legal action supporting pre-existing conditions MORE. The Ohio senator argued that not only would his bill protect the financial system, but also help community banks compete, which in turn could boost small business lending.

Under the proposals, a single bank could not hold more than 10 percent of the nation's banking deposits, nor take on more than 10 percent of the banking system's liabilities. Banks could take on no more than $1.3 trillion, or 2 percent of the nation's gross domestic product, in non-deposit liabilities. Non-banks could not take on more than three percent of GDP in liabilities, and could not grow larger than $436 billion.

Four existing banks — JPMorgan Chase, Bank of America, Citigroup and Wells Fargo — are currently above the size cap, and would need to be shrunk down if the bill became law, according to Miller's office.

The issue of "too big to fail" banks has been a rare topic that has attracted attention from both parties. Republicans maintain the Dodd-Frank financial reform law fails to address the problem of institutions so hefty their failure would threaten the entire financial system. And Democrats are calling for the nation's biggest banks to be broken up, and are ramping up pressure on the GOP to get on board.

Furthermore, some current and former regulators have also suggested breaking up the biggest banks, including the former head of the Federal Deposit Insurance Corporation, Sheila Bair, and Richard Fisher, the president of the Federal Reserve Bank of Dallas.

In addition to introducing the bill, Miller sent a letter to House Financial Services Committee Chairman Spencer BachusSpencer Thomas BachusManufacturers support Reed to helm Ex-Im Bank Manufacturers ramp up pressure on Senate to fill Ex-Im Bank board Bipartisan group of House lawmakers urge action on Export-Import Bank nominees MORE (R-Ala.) asking him to join the cause.

"Please consider this legislation in any future hearing on 'Too Big to Fail' financial institutions," Miller wrote. "Also, I would like the chance to include you on the list of the bill's cosponsors."

A spokesman for Bachus did not respond immediately to a request for comment.