WASHINGTON (Reuters) - Eight of the 10 largest donors so far to the U.S. presidential campaigns are Wall Street banks, led by Goldman Sachs, according to research on Thursday from a political watchdog group.

A view of 85 Broad Street where U.S. investment bank Goldman Sachs is headquartered in New York, March 5, 2008. REUTERS/Joshua Lott

Goldman and its executives have pumped $1.7 million into the races, with 70 percent going to Democrats Barack Obama and Hillary Clinton, despite former CEO Henry Paulson’s present job as treasury secretary for the Republican Bush administration.

The Center for Responsive Politics said that securities and investment firms altogether have donated about $33 million to presidential campaign coffers, more than any other sector of corporate America, except lawyers, the center said.

After Goldman, top-giving banks are Citigroup, Morgan Stanley, Lehman Brothers, Merrill Lynch and JPMorgan Chase, which is buying troubled rival Bear Stearns in a government-engineered bailout.

As the housing market crisis spreads and the economy stumbles, traditionally Republican-leaning Wall Street banks, many hit hard by bad bets on high-risk mortgage debt, are scrambling to shore up their ties with Democrats.

Sixty percent or more of contributions coming from Citi, Morgan, Lehman, JPMorgan and UBS AG have gone to Democrats, while Republicans have been favored by donors at Merrill and Credit Suisse, the center said.

Obama, a senator from Illinois, has taken in $6.7 million from securities and investment firms, with New York Sen. Clinton not far behind at $6.6 million, the center said in a report.

Arizona Sen. John McCain, the presumptive Republican nominee, has collected about $3 million from Wall Street.

Counting all sources of giving, Obama and Clinton have continued to raise more money in total than McCain, based on February fund-raising reports, the most recently available.

In that month, Obama collected $55.4 million; Clinton, $34.5 million; and McCain, $10.9 million, the center said, noting that the 2008 campaign will be the costliest ever.

“Obama and Clinton continue to take turns collecting the most from the securities and investment industry,” reflecting a pattern of the past few months, the center’s report said.

So far in the 2008 presidential campaign, the largest donor of all is ActBlue, a political action committee that has channeled $2.4 million in mostly small contributions to Democrats exclusively, including Obama and Clinton.

Besides ActBlue and the banks, other top givers include the law firms DLA Piper, Skadden Arps and Greenberg Traurig, as well as corporate giants Microsoft Corp and General Electric. More than 90 percent of gifts from media group Time Warner and its employees have gone to Democrats.

Another top giver, with donations so far of $569,000, is National Amusements Inc, a privately held movie theaters chain controlled by media mogul Sumner Redstone and the parent company of both CBS Corp and Viacom Inc.

The University of California and Harvard University have also been among the 25 largest contributors, the center said.