Now, faced with the prospect of even tougher regulations in President Barack Obama's second term, they have to build better ties with the new financial regulators he will appoint.
Obama lost the support of many bankers in the aftermath of the 2008 financial crisis and the passage of the 2010 Dodd-Frank financial reform law, which sought to shore up the financial system but also cost banks billions of dollars in annual profit.
The Democratic president has openly stated his distaste for "fat cat bankers" who "don't get it," and bankers fear more losses ahead if they cannot influence how the Dodd-Frank rules are implemented.
"He will continue to increase regulation, demonize and vilify businesses, and spend a lot of money, and tax people, and so forth," said Dick Kovacevich, a former Wells Fargo CEO and supporter of Republican challenger Romney.
Wall Street firms are also worried about Elizabeth Warren, whose victory in the Massachusetts Senate race may galvanize her to push for more regulations on bank lending to protect consumers. Warren was instrumental in creating the Consumer Financial Protection Bureau, which critics say could weigh down the economy with new regulations.
"I think the Obama win, along with Elizabeth Warren, will lead to more accountability and tighter regulation on Wall Street," said Chris Tobe, who advises pension plans as a principal at Stable Value Consultants and is a trustee of the Kentucky state pension fund. "Especially after a big shift to Romney from Wall Street, Obama I believe will be less likely to hold back on regulation this term."
People working in the U.S. securities and investment industry gave $20 million to Romney's campaign, versus $6 million to Obama, according to the Center for Responsive Politics. Four years ago, Obama received $16 million and Republican nominee John McCain only attracted $9 million.
"I voted for Obama in 2008 but obviously believed that Romney would be better able to handle the problems that we're confronting," said Scott Sperling, co-president of private equity firm Thomas H Lee Partners. "It is incumbent on us to work with the administration in a productive way to deal with these issues."
The new regulations come after the U.S. financial system nearly collapsed in 2008, forcing taxpayers to pour hundreds of billions of dollars into banks' coffers.
Many Americans believe the financial crisis was caused by banks' terrible judgment in areas like mortgage lending and securitization. Public support is strong for laws designed to make the financial system safer, even if bank profits suffer.
A 2010 Gallup poll showed that Dodd-Frank was Obama's most popular law, exceeding healthcare reform, for example. Few Washington lobbyists thought that Romney could fully repeal Dodd-Frank, because public support for the law is too high.
Big bank stocks fell on Wednesday morning with Goldman Sachs Group Inc down 5 percent at $119.91, and Citigroup Inc off 4.3 percent at $36.79.
RELATIONS WITH REGULATORS
Banks must now focus on softening regulations to the extent they can. Among the financial industry's top complaints are the Volcker rule, which prevents banks from making big bets in financial markets with their own money, and the Durbin Amendment, which limits the fees they can charge merchants for processing debit-card transactions.
Banks also want to scale back capital requirements, which cut into the returns banks can earn on their equity capital.
The industry had hoped to weaken the CFPB through steps like changing its structure to be headed by Democrat and Republican commissioners, but these steps are unlikely to gain much traction, analysts said.
"What I was told last night by Obama's win is, there will be no change to the CFPB in 2013," said Isaac Boltansky, a policy analyst at Compass Point Research & Trading in Washington.
Some banking industry lobbyists say their focus will be on the key regulators Obama is expected to name in his second term.
Major power players under Obama, including Treasury Secretary Timothy Geithner, are expected to step down, offering Wall Street a chance to reset relations.
Chairmen determine agendas at agencies such as the Securities and Exchange Commission (SEC) and Commodity Futures Trading Commission (CFTC), so Obama's choices to fill any open spots could affect how quickly new rules are implemented.
"If there was a different chair who had a different agenda, you could slow things down," said Bart Chilton, a Democratic commissioner at the Commodity Futures Trading Commission.
One possible replacement for Geithner, who has said he will not stay for a second Obama term, is White House Chief of Staff Jack Lew, a former Citigroup Inc banker.
"I hope Obama puts someone in who understands fiscal issues and who will have stature to work on the Hill to negotiate some type of package on fiscal reform," said Sheila Bair, former Federal Deposit Insurance Corp chairman.
SEC Chairman Mary Schapiro's term does not expire until June 2014, but speculation about her departure has been swirling for well over a year. Last month, she attempted to shoot down the rumors, saying she had not thought about her post-SEC plans.
SEC watchers speculate the job could go to SEC Commissioner Elisse Walter, a close friend of Schapiro's and a former executive at the Financial Industry Regulatory Authority, an industry-funded watchdog.
CFTC Chairman Gary Gensler's term technically expired in April. He is allowed to stay on as chairman until the end of 2013 and his renomination is an open question.
Gensler has been assailed by Republicans over his implementation of Dodd-Frank and criticized by lawmakers on both sides of the aisle following the collapse of futures brokerages MF Global and Peregrine Financial Group.
Much of Wall Street's regulatory agenda, however, is set to take a backseat in the short term due to the looming fiscal cliff -- a package of tax increases and federal spending cuts that will begin in January unless lawmakers act.
Bankers fear an impasse in solving the issue could spark an economic downturn that would hurt the industry.
In the longer term, banking lobbyists and other opponents of Dodd-Frank acknowledge that much is in the hands of rulemakers, and the best they can do is to try to beat back some rules with technicalities.
Paul Atkins, a Republican and former SEC commissioner, said he expects Dodd-Frank reform critics may have some success making narrow legal challenges and seeking to throttle reforms through congressional oversight.
"Dodd-Frank assigned a lot of powers to the regulatory agencies, so there is not much that Congress can do," he said.
"I expect that the Republican House would keep the pressure on through hearings, like they are doing now. People will also certainly take the fight to the courts."
Copyright 2010 by Reuters. All rights reserved.