Judgment due on Jamie Dimon For Jamie Dimon, it has all come down to this: A couple of hours in suburban Tampa will determine whether he emerges humiliated or triumphant. On Tuesday, Mr. Dimon, the chief executive officer and chairman of JPMorgan Chase & Co., will preside over the bank's annual meeting at one of its offices in Florida. The official business includes announcing the results of a shareholder vote on removing him from his role as chairman of the board. For Mr. Dimon, 57, the moment represents the most serious challenge to his leadership over his seven-year tenure. In recent weeks, the bank has reached out to shareholders, attempting to persuade them of the virtue of its argument - that it would be a mistake to fiddle with a management structure that has delivered record profits. The proposal's backers counter that a massive trading loss last year together with a series of regulatory messes demonstrate that the sprawling bank needs more independent supervision at the board level. The campaign to win votes - by both sides - has intensified. Earlier this month, two influential advisory firms threw their weight behind the shareholder proposal. Mr. Dimon, meanwhile, has received public avowals of support from fellow high-profile businessmen like Warren Buffett of Berkshire Hathaway Inc. and Jack Welch, the former CEO of General Electric Co. Mr. Dimon also has many defenders among the ranks of JPMorgan's shareholders, large and small. John Grandoff is a lawyer in Tampa who has a chunk of his retirement account invested in the bank's shares and is strongly opposed to separating the roles of chairman and CEO. "It's driven by a lot of folks who are anti-bank and do not understand how nimble a bank has to be these days," he said. The trading losses JPMorgan suffered - on complex credit bets placed by an employee nicknamed the "London Whale" - don't perturb Mr. Grandoff, who noted the bank still had a stellar year and increased its dividend. The vote could be a nail-biter. Last year, a similar proposal to split Mr. Dimon's dual role garnered 40 per cent of the vote; proponents say they expect that figure to rise this year. If the shareholder proposal doesn't receive majority support, Mr. Dimon will be chastened but face no real pressure. If the push does cross that threshold, however, the future of his dual role becomes murky. The bank's board would not be compelled to follow the recommendation of the proposal, which is non-binding. But directors would likely have to do something in response to such concrete shareholder concerns - or risk facing an even greater level of discontent in the future. In a meeting with investors earlier in May, Mr. Dimon reportedly floated the possibility that if the proposal succeeds, he might consider leaving the bank, according to The Wall Street Journal. Asked for comment about the report, JPMorgan spokesman Joseph Evangelisti said in an e-mail "Jamie has never threatened to leave the company." But some investors interpreted it that way. How do we get in a situation where he thinks he holds all the cards? This is a publicly traded company," said Lisa Lindsley of the American Federation of State, County And Municipal Employees, whose pension fund is one of the investors behind the proposal. We never intended this to be a referendum on his job as a CEO but he's made it that. On Mr. Dimon's watch, JPMorgan weathered the financial crisis in far better shape than many of its peers. But a series of recent troubles - trading losses, a congressional investigation, repeated probes by regulators - has blemished his record. For corporate governance experts, splitting the jobs of chairman and CEO between two people makes perfect sense. The joint role is the product of a time when the role of boards was to advise CEOs rather than to monitor them, said Charles Elson, a law professor who heads a centre for corporate governance at the University of Delaware. Why should the person being monitored oversee the group doing the monitoring? Prof. Elson said. It's not a personality issue, and when you make it a personality issue, you complicate it.