It is a recurring theme among liberal opinion writers when Democratic presidents appear unable to effectively govern: It’s not them, but the unwieldy structure of the American political system which is to blame.

With the ceiling caving in on President Barack Obama nearly midway through his second term, this theme has returned with a vengeance.

The latest culprit to serve as a source of vexation for the president is, according to former Harvard University President and Obama advisor Larry Summers, the 22nd Amendment to the Constitution which limits American presidents to just two terms in office.

From Roosevelt to Obama, Summers wrote, the start of a second term almost always marks the beginning of an American president’s least successful period in office. “This is why many scholars regard the current constitutional limit of two presidential terms as problematic,” he noted.

Summers does not, however, recommend the outright repeal of the 22nd Amendment. “[M]y guess is that problems caused by lame-duck effects are much smaller than those caused by a toxic combination of hubris and exhaustion after the extraordinary effort that a president and his team must exert to achieve reelection,” Summers noted.

This seems a more accurate conclusion, but Vox’s Matt Yglesias has a different take.

Summers flirted with the notion of amending the terms of the Constitution to allow for a single six-year term for the president, but Yglesias suggests that this is an impractical solution to the problem posed by Obama’s apparent lack of ability.

“The Confederate States of America operated under this plan, but didn’t have much success with it,” he noted on Wednesday. Indeed, the CSA didn’t enjoy much “success” in part because Jefferson Davis’s presidency was confined to a series of train cars forever evading the advancing Union Army by the middle of his fifth year in office.

“[G]overnors get better at governing when they’ve been in office longer,” he wrote. “But at the same time, governors who are eligible to run for reelection do better than governors who are ineligible.”

It could be that by rendering second-term presidents ineligible for future terms in office, the 22nd Amendment is slightly undermining the quality of governance by eliminating the basic mechanism of electoral accountability.

This is not entirely unreasonable, but ” the basic mechanism of electoral accountability” cannot apply eternally. Whether constitutionally or physically limited, a president will eventually determine for him or herself that another election is not going to be in the cards. Moreover, second terms are not wholly disastrous for presidents, even those who face strident opposition in the legislature.

“The recent history of two-term presidencies shows that things could be a lot better,” The New York Times was forced to concede in July of 2013 prior to a brief review of the legacies of the last four two-term administrations. “[A]ll four ultimately managed significant second-term accomplishments despite partisan opposition on Capitol Hill, leading historians to caution against predictions that the second Obama administration is doomed.”

Ronald Reagan passed both sweeping immigration and tax code reform in his second term. Bill Clinton struck a bipartisan agreement to balance the federal budget. It is at least possible to be a successful president in the second term in office, but that president almost always has to contend with a Congress stacked with members of the opposition party.

Some presidents are able to negotiate with their ideological opponents, and some are not. Obama is not, and all the excuses in the world for his failures are unlikely to reverse the looming verdict of history.