Along the way, Summers earned a "yes, but" reputation. Universally regarded as an almost uniquely brilliant economist, he was equally widely seen as arrogant and brusque. A favorite tactic was to finish the stories or arguments of others, which saved time but left legions of irritated associates in his wake. "He's just very direct and to the point. … He'd be much less exciting to talk to if he weren't so clear-headed and direct," says Rogoff, a Harvard colleague.
Summers realized by the late 1990s that his pile-driving approach was counterproductive, and he learned to throttle back. But doubts resurfaced when Obama opted to put him in a job at the NEC requiring the skills of an "honest broker" rather than return him to Treasury. Friends say Summers was determined to prove the skeptics wrong by running an even-handed policy process.
"It's been a remarkable transition stylistically from where he was 20 years ago, even 10 years ago. Stylistically, it's like night and day," says David Smick, CEO of financial advisory firm Johnson Smick International, who's known him since the late 1980s.
Still, Summers can sometimes appear to be a man feigning calm rather than possessing it. And he remains a controversial figure within the Democratic Party, where some see his enthusiasm in the 1990s for market solutions and deregulation as having sown the seeds that sprouted into today's crisis. Along with then-Treasury secretary Robert Rubin, Summers opposed regulating derivatives, including credit default swaps, and supported repealing the Glass-Steagall Act, which prohibited banks from simultaneously engaging in investment and commercial activities.
"I think he shares the blame," says economist Dean Baker of the Center for Economic and Policy Research, a left-of-center Washington, D.C., think tank.
Summers acknowledges some regrets, though with caveats. If he had known that unregulated derivatives would mushroom and that regulators would remain spectators, he would have acted. "With hindsight, all of us with involvement in financial policy wish we had done more to forestall problems," he says.
His allies say Summers has become the indispensable man of Obama administration policymaking, a sort of economic consigliere for the president. If Obama decides to replace Fed Chairman Ben Bernanke when his term expires at the end of January, Summers is a likely successor.
"He can provide one-stop shopping for analytical rigor on a breadth of economic and financial matters like no one else in the world," says Gene Sperling, a counselor to Treasury Secretary Timothy Geithner.
No champagne yet
Summers' modest West Wing office provides few hints of his prominence. There's a small corner refrigerator stocked with Diet Cokes. A wall-mounted photo of Obama and his economic SWAT team at work. Another signed "Al Gore." But as head of the NEC, a Clinton administration creation, Summers enjoys ample amounts of that key Washington currency: presidential face time. Every morning, he makes the short journey down one level to the Oval Office, where he leads a daily economic briefing for Obama, an innovation the new president put in place to keep tabs on the metastasizing financial crisis.
"There were periods when every day — one way or another — was about the financial crisis," Summers said in an interview. "But as there's been a little bit of a return to normality, there's been a little bit more of a movement toward a broader range of topics."