The securities and investment industry gave 2 to 1 to Democrats in early 2009 but sent nearly half its donations to Republicans by year's end, according to data complied by the Center for Responsive Politics for the Post.
The commercial banking industry and its employees gave nearly twice has much to Republicans during the last three months of 2009, the newspaper reported.
With all 435 seats of the House of Representatives and more than a third of the 100 U.S. Senate seats up for grabs in November congressional elections, the money is going to matter. Voters frustrated over a staggering economy could help Republicans reduce Democratic margins in Congress.
President Barack Obama, the Democrat who took office in January 2009 in the midst of a colossal government bailout of failed banks, has pushed for financial regulatory reforms including curbing risky trading by banks and linking executive pay to long-term performance.
Obama drew a larger share of Wall Street financial backing than his Republican rival, John McCain, in the 2008 presidential campaign, according to the newspaper, and analysts noted the Democrats still pulled in more money overall than Republicans from Wall Street in 2009.
The shift toward Republicans came later in the year -- as the financial reform debate heated up -- and was most evident among commercial banks, which have traditionally tilted Republican, the report said.
The report cited JP Morgan Chase, headed by Obama supporter Jamie Dimon, as having scaled back its giving to Democrats.
The bank and its employees, who doled out nearly $500,000 in federal contributions last year, went from giving 76 percent of the money to Democrats in the first quarter to giving 73 percent to Republicans in the fourth, the newspaper said.
(Writing by Doina Chiacu; Editing by Dominic Evans)