WASHINGTON — Just over three years ago, early in his uphill campaign for president, Senator Barack Obama wrote to the Federal Reserve chairman and the Treasury secretary calling for a summit conference to address signs of trouble in the housing and financial markets.

While Mr. Obama could not have known how bad things would get, then as now he saw a muscular role for government in enforcing regulations in the public’s interest, while weighing them against the industry’s interests so both would benefit.

It is an approach that he is likely to outline again on Thursday, as the president speaks near Wall Street in a bid to make the closing argument for the regulatory overhaul now before the Senate.

“Throughout our history there have been times where the financial sector swung way out of balance,” Mr. Obama said on Wednesday in an interview with CNBC and The New York Times, citing the period that led to the Depression as the primary example.