Congress makes its return to Capitol Hill this week, with a busy agenda following the 2024 presidential election, as Republicans gained control in the Senate and are projected to maintain control in the House.

House Speaker Mike Johnson said in a Tuesday press conference that there are "preliminary plans" for President-elect Donald Trump to come to Capitol Hill to meet with House Republicans the same day that he's scheduled to meet with President Biden at the White House. Across the halls of Congress on Wednesday, the Senate will also hold elections for the next majority leader to replace Republican leader Mitch McConnell, who is stepping down at the end of the year.

The three GOP Senators running in the secret ballot election are: Minority Whip John Thune of South Dakota, John Cornyn of Texas and Rick Scott of Florida.

Over the weekend, as news of his choices for key Cabinet positions began to roll out, Trump had a message for the candidates in a social media post, saying, "Any Republican Senator seeking the coveted LEADERSHIP position in the United States Senate must agree to Recess Appointments (in the Senate!), without which we will not be able to get people confirmed in a timely manner."

This isn't Trump's first objection to the required Senate confirmations for Cabinet nominees. As a way to get around them during his first administration, many of his Cabinet-level positions were filled by those serving in an "acting" capacity, meaning the authority was delegated to a subordinate who didn't need to be confirmed by the Senate. As a result, Trump's Cabinet saw more turnover than any other recent president, the Washington Post reported.

So, what are “recess appointments”? Here’s what Trump is referring to:

What is a recess appointment?

In regular circumstances, a newly inaugurated president will nominate various individuals to fill government positions in the executive and judicial branches, including Cabinet secretaries, ambassadors and federal judges. Many (though not all) of those nominees must appear before the Senate for a confirmation hearing, where they are asked questions about their qualifications and how they will perform their duties in the position for which they were nominated. A simple majority vote in the Senate is needed in order for the person to be confirmed to the position. This is designed to serve as a form of checks and balances on the power of the presidency.

A recess appointment, however, allow presidents to install their nominee to the position while the Senate is in recess, without a confirmation hearing or vote, according to the Recess Appointments Clause in the U.S. Constitution. It says: "The President shall have Power to 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."

So this means if a president manages to make a recess appointment, that individual’s term would only last for about two years. At that point, the person could be appointed again through the same recess appointment or through the regular Senate confirmation process.

Are there any limitations or guidelines?

Recess appointments are allowed only when the Senate is out of session for 10 days or more. In 2014, the U.S. Supreme Court gave the Senate more authority to curtail the use of recess appointments following three controversial recess appointments to the National Labor Relations Board made by President Barack Obama in 2012 during a three-day break. In a 9-0 decision, the Supreme Court ruled that three days is "too short a time to bring a recess within the scope of the Clause."

The Senate has used “pro forma” sessions when lawmakers are out of town, or short meetings that don’t involve official business, as a way to prevent a president from bypassing confirmation votes. This could simply entail a senator gaveling in and then calling the session over.

What other presidents have used recess appointments?

Recess appointments were meant to be used only in the event of an emergency. But in recent decades, they've been used as a political tool to get around congressional opposition.

During Trump’s first presidential term in 2020, he threatened to adjourn Congress during the thick of the COVID-19 pandemic so he could make recess appointments, but that threat never came to fruition.

According to the Congressional Research Service, former President Obama made 32 recess appointments while in office; Bill Clinton made 139 and George W. Bush made 171.

How have the 3 GOP contenders for Senate leadership responded to Trump’s demands?

All three contenders seem to agree that Trump should be able to make recess appointments, even though the GOP already holds a majority in the Senate. As Trump indicated in his social media post, he wants his nominees for top positions to be appointed without delay. A recess appointment would also avoid the public scrutiny that a Senate hearing could bring, creating the risk that some Republicans could defect over a highly controversial pick.

Sen. Scott replied to Trump's social media post, saying "100% agree. I will do whatever it takes to get your nominations through as quickly as possible."

While Sen. Thune told Fox News Digital that "all options are on the table." And Sen. Cornyn, Thune's chief rival, posted on social media that the Constitution "expressly confers the power on the President to make recess appointments."