Pakistan, Nov. 5 -- America has spoken, and the message from Tuesday's midterm elections could not be any louder. Far exceeding most pre-election forecasts, Democrats have wrested control of both chambers of Congress, scoring historic victories in Republican strongholds such as Texas, Kansas and South Carolina. Two years after returning to the White House with promises of cheaper groceries, secure borders and an end to costly foreign entanglements, President Donald Trump confronts an electorate increasingly unwilling to take those promises at face value.

The data speaks for itself. Nearly nine in ten voters considered living costs a major concern. Roughly seven in ten wanted Congress to impose greater checks on presidential power. Two-th...