Lashing out at what he called “corporate deserters,” President Obama on Thursday increased the pressure on Congress to approve legislation targeting companies that change their address to slash their U.S. tax bill.

Obama, speaking at a technical college in Los Angeles, said corporations were taking advantage of a loophole not available to average workers — and in the process, forcing the middle-class to take up more of the tab for infrastructure and job-training programs.

“I don’t care if it’s legal. It’s wrong,” Obama told the California crowd. “You don’t get to choose the tax rate you pay. These companies shouldn’t either.”

Obama pressed Congress to enact a measure making it impossible for a U.S. corporation to swallow up a smaller foreign company in order to avoid paying U.S. taxes.

In the process, Obama echoed his Treasury secretary, Jack Lew, who last week called for a “new sense of economic patriotism.”

Obama’s comments put an even larger spotlight on the practice known as inversions, an issue that meshes well with the economic populist tone that Democrats are taking this election year.

The White House is echoing the push from congressional Democrats to enact anti-inversion legislation retroactive to May, and has brushed aside Republicans who say the cross-border deals should be dealt with in tax reform.

Tax reform, Obama said, is “going to take some time,” while the recent rash of inversions illustrates that Congress needs to act to stop those deals now....