”I do solemnly swear that I will faithfully execute the Office of President of the United States, and will to the best of my ability, preserve, protect and defend the Constitution of the United States. So help me God.”

So Donald Trump pledged on Jan. 20, 2017. Now he must keep those words.

Regardless of what he told supporters who traveled from across Minnesota, Wisconsin and beyond to hear him Thursday, Oct. 10, 2019, in Minneapolis -- that he won’t cooperate, that he has no intention of answering to House leaders, that he has done nothing illegal -- he must answer to the legislative branch in its impeachment inquiry.

The Constitution gives the legislative branch the power to hold the executive branch accountable. The document reads: “The President, Vice President and all Civil Officers of the United States, shall be removed from Office on Impeachment for, and Conviction of, Treason, Bribery, or other high Crimes and Misdemeanors.”

Impeachment has roots in British constitutional history, when a 14th century parliament instituted means to hold the king’s ministers accountable for their public actions. Almost 400 years later, the colonists who broke away from England saw impeachment as a vital safeguard for their fledgling republic. Fearing the potential for abuse of executive power and having suffered mightily because of King George’s abuses, the founders considered impeachment so important that they made it part of the Constitution before they defined the contours of the presidency, according to the U.S. House Art & Archives.

Impeachment differs from civil or criminal court. In the words of Alexander Hamilton at the time, impeachment involves the “misconduct of public men, or in other words from the abuse or violation of some public trust.”

Citizens, whether supporters of Trump or detractors, can take heart that we have a system of checks and balances with legislative, executive and judicial branches. There also is an internal check-and-balance in impeachment. In a two-step process, the House of Representatives has “the sole power” to impeach an official, and then the Senate is “the sole court” for impeachment trials.

If Trump has done nothing wrong, as he vociferously contends, then he and supporters have nothing to fear. He must adhere not only to the letter of the law but the spirit of the law. He must cooperate with Congress.

We need the president to stand by and for the Constitution, so help us God.