Shutdowns of the federal government usually don’t leave much economic damage. But the one that started Wednesday looks riskier, not least because President Donald Trump is threatening to use the standoff to permanently eliminate thousands of government jobs. For now, financial markets are shrugging off the impasse as just the latest failure of Republicans and Democrats to agree on a budget and keep the government running. But Trump's massive layoff threat and the precarious state of the American economy raise the odds of longer-lasting damage.