After the Supreme Court struck down President Biden’s plan to cancel billions of dollars in student loan debt, borrowers wondered how he would make good on his promise to tackle debt burdening millions of Americans.

The answer: He would do it bit by bit.

Mr. Biden on Wednesday canceled $1.2 billion in student loan debt, bringing the total amount that he has wiped out during his time in office to $138 billion for 3.9 million borrowers. It is a far cry from his initial plan, which would have canceled up to $400 billion in debt for about 43 million borrowers.

But even Mr. Biden’s critics acknowledge that he has gone further than any of his predecessors in relieving the debt burden for millions of borrowers.

“It’s good for the economy as a whole,” Mr. Biden said on Wednesday, speaking to a small crowd at a library in Culver City, Calif. “By freeing millions of Americans from the crushing debt of student loan programs, it means they can finally get on with their lives.”

To work around the Supreme Court decision, Mr. Biden has pursued a more piecemeal approach, tweaking existing programs long plagued by bureaucratic delays. The debt cancellation he announced on Wednesday was an example of that, affecting about 150,000 borrowers enrolled in what is known as the SAVE plan, an income-driven repayment program, who have lower balances and have made payments for at least a decade.

While his administration has periodically announced such limited forms of debt cancellation in the past year, Mr. Biden’s stop to personally address the issue during a fund-raising swing through California appeared to reflect a White House intent on getting more credit for it. Democratic allies have been pleading for the administration to emphasize debt cancellation to galvanize crucial constituencies, including the young voters and Black borrowers who disproportionately shoulder such debt.