The U.S. Senate’s failure to convict former President Donald Trump for instigating the Jan. 6 riot in the Capitol, for which the House of Representatives had impeached him, leaves the question of whether Congress has any effective means of holding a president to account for acts against the Constitution.

The nation’s Founders had sought to prevent a president from enhancing his own powers to the point of becoming, in effect, a king. Under Trump, America’s constitutional system had a dagger pointed to its heart: a president who refused to recognize that he had lost an election and was willing to use a mob to physically attack a supposedly co-equal branch.

America’s Founders made conviction by the Senate, which brings removal from office, for an impeachable offense — which need not be a statutory crime — very difficult by requiring a two-thirds vote. A president, they believed, should not be removed from office as a result of a national mood swing.