The U.S. government, in contrast, has no extra money to launch a sovereign wealth fund. The federal government is $35 trillion in debt and has been running sizable budget deficits for more than two decades. What’s more, its budget problems are expected to worsen in the coming years. Social Security obligations are growing, as are health-care payments for an aging population. ...

A sovereign wealth fund would be a way for a president to have access to money without having to deal with Congress. But as such, it could quickly become a dangerous slush fund. Theoretically, an independent board could manage the fund; some advocates point to the Federal Reserve as a model. Norway’s fund is managed by a team at its central bank. But keep in mind that Trump has considered firing the Fed chair. Imagine what would happen if the sovereign wealth fund lost money on a key investment or refused to fund a president’s pet project. The concept comes with myriad risks and few clear benefits.