Divided government has been a staple of American politics for many years, and Mr. Obama, a former professor of constitutional law, needs no education in the system of checks and balances. But analysts usually emphasize other factors. In ideological terms there is a Tea Party-caffeinated insurgency within the House Republican caucus. In personal terms, there is Mr. Obama’s inability to charm adversaries as Ronald Reagan did. And while the executive branch’s role in national security has grown mightily in recent decades, Mr. Obama’s decision to go to Congress arguably shows a greater deference on war and peace than any president since Franklin D. Roosevelt.

BUT what if the problem isn’t a matter of ideology or personality? What if it is structural and institutional? This is the case some political theorists have been making for many years.

“The actual form of our present government is simply a scheme of congressional supremacy,” one close student of politics, Woodrow Wilson, wrote in his book “Congressional Government,” published in 1885, when Wilson was not yet 30, and when a succession of weak presidents — Ulysses S. Grant, Rutherford B. Hayes, Chester A. Arthur — seemed unable to master the uses of power.

Wilson did not fault individual presidents. Instead he pointed to the weakened condition of the presidency itself. “Its power has waned,” Wilson wrote. “And its power has waned because the power of Congress has become predominant.” As the nation got bigger, so did the House of Representatives. But it also became more atomized. Its “doings seem helter-skelter, and without comprehensible rule,” Wilson wrote.