He went so far as to call the reforms "the strongest consumer protections in history." The president added to a burst of applause: "Because of this law, the American people will never again be asked to foot the bill for Wall Street's mistakes."
Republicans portray the bill as a burden on small banks and the businesses that rely on them and argue it will cost consumers and impede job growth. Republican Rep. Darrell Issa of California called Obama's bill-signing a "charade" that ignored the root causes of the financial crisis.
The president said otherwise. He argued that a crippling recession was primarily caused by a breakdown in the financial system that cannot happen again.
"I proposed a set of reforms to empower consumers and investors, to bring the shadowy deals that caused this crisis into the light of day, and to put a stop to taxpayer bailouts once and for all," Obama said to supporters. "Today, thanks to a lot of people in this room, those reforms will become the law of the land."
In a note of irony, Obama signed the bill with great fanfare in the massive Ronald Reagan Building, named after a president who championed deregulation.
The president was joined by scores of consumer advocates, state and local government officials, business owners and executives, and members of Congress who supported the bill. Obama singled out for praise Sen. Chris Dodd, D-Conn., and Rep. Barney Frank, D-Mass., who shepherded the bill through Congress.
In the midst of a heated midterm election season for many lawmakers, Obama sought to put the complex law in consumer-oriented terms for the nation. He said it would help root out fine print and hidden fees for people, and provide deeper scrutiny of the sophisticated financial transactions on Wall Street.
The law also assembles a powerful council of regulators to be on the lookout for risks across the finance system. Large, failing financial institutions will now be liquidated and the costs assessed on their surviving peers. Borrowers will be protected from hidden fees and abusive terms, but also will have to provide evidence that they can repay their loans. The Federal Reserve will get new powers while at the same time coming under expanded congressional oversight.
"While President Obama pats himself on the back today, families and small businesses are bracing for yet another big-government overreach that will make it harder to create new jobs," said the House Republican leader, John Boehner of Ohio.
Though Obama and his top officials urged Congress to pass the law while the memory of the 2008 financial crisis was still fresh, many of the law's provisions won't take effect for at least a year, as regulators scramble to write new rules and implement them.
Large Wall Street banks have welcomed some provisions in the bill, but have fiercely opposed others that would limit their banking business and cut into their profitability.
Obama has at least one contentious remnant from the bill to address. He must still nominate a director for the independent consumer protection bureau, an agency that became one of the bill's flashpoints and was attacked by Republicans as a broad expansion of government power over private business.
Elizabeth Warren, a Harvard law professor, is considered a leading candidate for the job. As head of the Congressional Oversight Panel for the government's $700 billion Troubled Asset Relief Program, the bank rescue fund known as TARP, she has periodically clashed with Treasury Secretary Timothy Geithner.
Liberals and unions have been aggressively pressing for her appointment. AFL-CIO President Richard Trumka was among the latest to voice support for of Warren, saying Tuesday she is the only candidate "uniquely qualified and equipped to head this new agency."
But opposition in the Senate could make Warren's confirmation difficult, a point Dodd made in a radio interview on NPR Monday. White House spokeswoman Amy Brundage said that while the administration has additional candidates in mind, "We are confident she is confirmable."
Also under serious consideration is assistant Treasury secretary Michael Barr, one of the architects of the financial regulation bill and a close ally of some White House officials. Deputy assistant attorney general Eugene Kimmelman is also in the running for the slot.