The case for suing the president

The separation of powers also guarantees political accountability. When Congress makes a law and the president executes it as written, citizens will know whom to reward or punish at the next election.

A president who unilaterally rewrites a bad or unworkable law, however, prevents the American people from knowing whether Congress should be praised or condemned for passing it. Such unconstitutional actions can be used to avert electoral pain for the president and his allies.

If Mr. Obama can get away with this, his successors will be tempted to follow suit. A Republican president, for example, might unilaterally get the Internal Revenue Service to waive collection of the capital-gains tax. Congress will be bypassed, rendering it increasingly irrelevant, and disfranchising the American people.