A federal appeals court in Washington, D.C., struck an important blow against the imperial pretensions of the modern presidency last month, when it declared unconstitutional three of President Barack Obama’s appointments to the National Labor Relations Board.

Normally, important officials in the executive branch of government are chosen by the president with the “advice and consent” of the Senate.

Because the confirmation process has become increasingly contentious, modern presidents have increasingly availed themselves of a constitutional loophole, which provides that the president may “fill up all vacancies that may happen during the recess of the Senate, by granting commissions which shall expire at the end of their next session.”

Such “recess” appointments are only temporary, but because they do not require Senate confirmation, they can be used to put into office controversial figures who would not win the requisite support in the Senate.

President Bill Clinton made 139 such appointments in his two terms as president, and George W. Bush, 171. Obama has made far fewer — only 32 so far — but he has in one significant way expanded the practice.

At issue is what “the recess” of the Senate is. Presidents Clinton and Bush interpreted the provision to refer to any adjournment of more than three days that had been voted by both Houses of Congress. (Article I, Section 5 of the Constitution holds that “Neither House, during the Session of Congress, shall, without the consent of the other, adjourn for more than three days.”)

When the Democrats regained control of the Senate in 2007, they acted to prevent Bush from making recess appointments by holding “pro forma” sessions of the Senate every three days, so as to avoid creating any “recess” during which Bush could make an appointment.

When Republicans took control of the House in 2011, they used the Democrats’ strategy against Obama, refusing to consent to adjournments of more than three days, thus requiring the Senate to hold “pro forma” sessions when it was not conducting regular business.

Unlike Bush, Obama did not see these “pro forma” sessions as creating any bar to his making recess appointments. He argues that the Senate is constitutionally in “the recess” any time he determines that it is not doing business, no matter how short the adjournment.

When the NLRB members’ appointments were challenged, some observers expected the appeals court to focus on the question whether the “pro forma” sessions of the Senate did or did not prevent creating a “recess” during which the president could make an appointment.

Instead, the court unanimously reached a much broader conclusion, rejecting not only Obama’s interpretation of the Recess Appointments Clause but also the interpretations favored by Presidents Bush and Clinton and all their recent predecessors — and, in the process, rejecting the conclusions of another federal appellate court.

The Washington circuit court, however, makes two powerful arguments, one relating to the structure of our government, the other based on the text of the Constitution.

The Constitution allows the president to make unilateral appointments not during “any recess” or “a recess” but during “the recess of the Senate.”

“The recess” is singled out with the definite article to mean something specific — in the court’s view, the time when one full session of the Senate ends, after the Senate adjourns “sine die” without any further date designated.

The Constitution speaks repeatedly of “adjournments” of the legislature, and if “the recess” of the Senate were to be read as Bush or Obama interpreted it, the text should have been written to say that the president may make appointments during “any adjournment” of the Senate.

The document, however, does not say that, and when the text is clear, we must do what it says, not what we wish it had said. Structurally, the court’s reading also makes sense: Either the Senate is in session, which means that the Senate can, if it wishes, act on presidential nominations, or it is in “the recess,” when it cannot act.

Presidents of both parties have resisted this interpretation, because they do not like what the Senate, with its cumbersome procedures, so often chooses to do — to delay action or to allow a minority of its body to defeat nominations.

Presidents don’t like having their power limited, but such limits are an essential part of the constitutional design, which makes the legislature superior to the executive. Partisan politicians argue for and against such limits as it suits their partisan agendas. That’s why we need the courts to impartially protect the liberties of all.

Joseph R. Reisert is associate professor of American constitutional law and chairman of the department of government at Colby College in Waterville.