Gary Cohn is facing the most difficult investment dilemma of his career. The former Goldman Sachs president helped steer the bank to safety during the financial crisis. Now he's under pressure to abandon President Donald Trump, whom he serves as chief economic advisor. Remaining could hurt his reputation, but he's been a moderating influence on trade and he's also a point man on tax reform. Losing his Wall Street savvy would further damage the White House — and the country.

Cohn built his career at the fast-paced trading desks of Goldman, where risk is often calculated in seconds. As No. 2 during the economic meltdown, he helped lead the bank in preparing for the mortgage market's decline as competitors were bulking up on those assets. Goldman still needed a $5 billion infusion from Warren Buffett's Berkshire Hathaway but it survived in better shape than its competitors, some of whom disappeared.

His Wall Street reputation made him an attractive candidate for Trump, despite his Democratic Party affiliation. Centrists welcomed Cohn as director of the National Economic Council as a moderating force. He's been a strong counter to Chief Strategist Steve Bannon, who in an interview with American Prospect talked of fighting with Cohn and an "economic war" with China. Cohn helped to indefinitely delay steel tariffs that could spark a trade battle with Beijing. He is also a point man on Trump's push for tax reform, where his deal-making skills will come in handy with Congress. But he wasn't able to persuade Trump to stay in the Paris climate agreement.