Experts say the United States needs to spend more on repairing and modernizing the nation’s aging infrastructure, and President Trump and congressional Democrats have offered trillion-dollar plans. A key difference: Democrats want to use only federal money, while Trump says a $200 billion federal investment would attract $800 billion in spending by businesses and state and local governments. Neither plan, however, stipulates where the funds would come from or what projects they would cover, although Trump is calling for selling government facilities and “slashing regulations” to speed construction. Experts say the needs extend beyond traditional infrastructure to high-speed internet, a more secure and versatile electric power grid and hacker-resistant communications. Some question the call to invest trillions in infrastructure, saying that U.S. infrastructure has been consistently improving in recent decades, that its quality is comparable to that of other advanced countries, and that spending advocates have conflicts of interest.