Economists and investors will be looking for one thing above all from President Donald Trump’s speech to the nation Tuesday night: What will his promised tax cuts look like? Which Obama-era regulations will be reversed? Will he push for an infrastructure spending plan this year? Trump’s broad campaign promises to sharply cut taxes, reduce red tape and boost spending on infrastructure have helped lift the stock market to record highs. Yet without some further guidance on specific plans, investors might grow impatient.