Trump promised to shrink the trade deficit. Instead, it exploded.

Over the past year, even as he imposed tariffs on foreign-made solar panels, washing machines, steel, aluminum and assorted goods from China, imports roared ahead of exports.The president thus begins his reelection drive with a core campaign promise unfulfilled — and with a recent flurry of economic research showing that his embrace of tariffs is damaging the U.S. economy.Economists say the trade deficit is swelling because of broad economic forces, including a chronic shortfall in national savings that was exacerbated by last year’s $1.5 trillion corporate and personal income tax cut. The Commerce Department on Monday began investigating whether imports of titanium sponges, used in chemical plants and military hardware, represent a national security threat.The president has used similar studies to impose tariffs on steel and aluminum and has threatened to apply them to imported cars and car parts.Trump persists with the import levies even as some supporters also push for him to act on other forces fueling the trade deficit, including a robust dollar.The dollar is now valued 19 percent above its 10-year average against the currencies of major U.S. trading partners, according to Federal Reserve data.The high dollar acts as a price increase for American exporters, making it harder to compete with foreign rivals.“A competitive dollar is the most important tool we have to spur economic growth and job creation in the U.S. economy,” said Michael Stumo, chief executive of the Coalition for a Prosperous America.[China has a big weapon that it hasn’t used in the trade war — yet.