There was a time in Washington when Jamie Dimon, chairman and chief executive of JPMorgan Chase, was regarded as the sage of Wall Street. But a series of congressional investigations and regulatory actions against the bank have tarnished that reputation and fueled a shareholder uprising that raised doubts about his leadership.

On Tuesday, the charismatic leader fended off an attempt by union group AFSCME, the New York City Comptroller’s Office and fund managers to take his chairmanship role away, leaving him solely as chief executive. Despite the effort, only 32 percent of JPMorgan shareholders approved the proposal at the bank’s annual meeting in Tampa, demonstrating the confidence that shareholders have in the outspoken leader.

While that was lower than previous years, the clamor leading up to the vote bruised the reputation of a man who had been widely praised for running one of the strongest banks to emerge from the 2008 financial crisis. Dimon, 57, has led JPMorgan to record profits in the past three years while most of its competitors struggled with troubled loans and bad bets from the economic meltdown.

In a statement, Dimon was gracious in victory.

“We appreciate the support shown by shareholders and the thoughtful way many have engaged with us as they determined how to vote on these issues,” said Dimon. “We take the feedback from shareholders very seriously and we will continue to build toward being best in class in corporate governance.”

The question of reducing Dimon’s dual roles at JPMorgan, the country’s largest bank, gained momentum last year, a few days after the bank revealed it had suffered a multibillion-dollar trading loss. The damaging bets, initiated by a trader known as the “London Whale,” ultimately cost the bank at least $6.2 billion.

Policymakers in Washington were alarmed by the trading fiasco but continued to hold the bank and its chief in high esteem. Even when Dimon appeared before the Senate to explain how the country’s biggest bank could lose billions on bad bets, lawmakers sought his advice.

By March, however, the deference paid to Dimon and JPMorgan waned. A 300-page report from the Senate’s Permanent Subcommittee on Investigations suggested that Dimon was less than forthright with regulators as he learned of the botched trades.