The need for hefty investment in America's infrastructure was one of the few unifying themes of the country's raucous election. Just ahead of the vote last November, two of President-elect Donald Trump's lieutenants drafted a superficially appealing outline to attract a whopping $1 trillion in private-sector funding. The tax credits involved are a potential giveaway to businesses and investors. Other assumptions are fanciful, too.

The plan's co-authors, Wilbur Ross and Peter Navarro, have since been selected respectively as Trump's commerce secretary and the head of a new White House trade advisory group. The U.S. Senate has delayed Ross's confirmation hearing until next Wednesday because Ross hasn't completed the necessary paperwork. Lawmakers shouldn't let partisan concerns distract them from probing how he aims to promote investment in highways, railroads, airports, fiber networks and other infrastructure.