Wall Street is one of the biggest sources of funding for presidential campaigns, and many of the Republican Party's potential 2016 contenders are governors. And so, last week, the GOP filed a federal lawsuit aimed at overturning the ... law that bars those governors from raising campaign money from Wall Street executives who manage their states' pension funds. In this case, New York's and Tennessee's Republican parties are represented by two former Bush administration officials, one of whose firms just won the Supreme Court case invalidating campaign contribution limits on large donors. In their complaint, the parties argue that people managing state pension money have a First Amendment right to make large donations to state officials who award those lucrative money management contracts. With the $3 trillion public pension system controlled by elected officials now generating billions of dollars worth of management fees for Wall Street, Securities and Exchange Commission regulators originally passed the rule to make sure retirees' money wasn't being handed out based on politicians' desire to pay back their campaign donors. The suit comes only a few weeks after the SEC issued its first fines under the rule - against a firm whose executives made campaign donations to Pennsylvania Gov. Tom Corbett, a Republican, and Philadelphia Mayor Michael Nutter, a Democrat. In a statement on that case, the SEC promised more enforcement of the pay-to-play rule in the future. The GOP lawsuit aims to stop that promise from becoming a reality.