In a Capitol Hill hearing Wednesday, Democrats pushed JP Morgan CEO Jamie Dimon on the bank’s $2 billion trading loss while Republicans courted his opinion on financial regulation.

Jamie Dimon, chief executive officer of JPMorgan Chase & Co., arrives to a Senate Banking Committee hearing in Washington, D.C., U.S., on Wednesday, June 13, 2012. Photographer: Andrew Harrer/Bloomberg

From 1989 to 2009, the banker and his wife gave over half a million dollars to Democrats, according to a Center for Responsive Politics analysis. That’s 12 times what they gave to Republicans during that same time frame.

Dimon has given money to politicians in both parties over the years, in particular senators who oversee the banking industry. But the bulk of his funds have gone to Democratic politicians. He gave $50,000 to Obama’s inaugural committee after giving $2,300 to Hillary Clinton in the 2008 primary.

He’s “one of the few Democratic C.E.O.’s in that line of work,” Rep. Barney Frank (D-Mass.) said of Dimon in 2009.

But Dimon has become one of the highest profile critics on Wall Street of Dodd-Frank, the financial regulation reform packaged pushed and passed by Democrats last year. And so far this cycle his donations are more divided — he has given $6,800 to Democratic candidates and $4,500 to Republicans. He has not given to President Obama’s reelection campaign.

Overall donations from JPMorgan Chase PACs and employees trended Democratic through 2008 but have now swung Republican, the Center for Responsive Politics reports.

Nineteen of Obama’s top 2008 donors from the financial sector are supporting former Massachusetts governor Mitt Romney this cycle, according to Politico. One of the main reasons, Politico reports, is Dodd-Frank. That doesn’t mean Dimon will join them — but it will be interesting to watch his campaign contributions going forward.