Mitch McConnell, the highest ranking Senate Republican and the longest serving Senate leader in U.S. history, announced Wednesday that he would step down from his position at the end of November.

“One of life’s most underappreciated talents is to know when it’s time to move on to life’s next chapter. So I stand before you today … to say that this will be my last term as Republican leader of the Senate,” McConnell, who became Majority Leader in 2015, said in remarks on the Senate floor.

While stepping down from the leadership role he has held for 17 years, McConnell, 82, said his health was not the determining factor for his decision and that he would serve out the remainder of his term, which lasts until January of 2027.

Here’s a look back at six key moments in McConnell’s career as Republican leader.

Crusade against Obama — and Obamacare

In an interview in October 2010, McConnell was quoted as saying, “The single most important thing we want to achieve is for President [Barack] Obama to be a one-term president.” A core piece of McConnell’s crusade against the then-president was his staunch opposition to the Affordable Care Act, Obama’s signature healthcare insurance law.

He rallied Republicans to vote against it in 2010, and vowed in 2016 to overturn the law without a replacement plan in place, before ultimately coming to the realization that Republicans did not have the votes to do so.

“I regret that the effort that we repeal and immediately replace Obamacare would not be successful,” he said .

In 2022, Republicansn to do away with the healthcare law.

Denying Supreme Court nominee Merrick Garland a vote

In 2016, McConnell initiated a new, and highly controversial standard when he announced that he would not allow a vote on whoever then-President Barack Obama would nominate to fill Justice Antonin Scalia’s seat on the Supreme Court. McConnell’s rationale was that the vacancy had come too close to the next presidential election, and the appointment of a new judge should wait until the American people had selected the next commander-in-chief.

“The American people should have a say in the court’s direction,” McConnell told reporters at the time. “It is a president’s constitutional right to nominate a Supreme Court justice, and it is the Senate’s constitutional right to act as a check on the president and withhold its consent.”

Obama selected centrist judge Merrick Garland as his choice to fill Scalia’s seat, but was never given a Senate vote, a decision that would solidify conservative control of the court after Donald Trump was elected president in 2016 and would go on to have three justices confirmed.

Approving Trump judges

While McConnell was the roadblock to Garland’s Supreme Court nomination, he was also the driving force in helping Trump confirm an unprecedented number of court appointments.

All told, McConnell was able to shepherd 175 district court appointments, 54 court of appeals judgeships and three Supreme Court justices through the Senate and onto the bench.

Vote to acquit Trump

After the Jan. 6, 2021, riot at the U.S. Capitol by Trump’s supporters who were seeking to block the certification of the 2020 election, McConnell was outspoken about who was to blame for the violence.

“The mob was fed lies. They were provoked by the president and other powerful people, and they tried to use fear and violence to stop a specific proceeding of the first branch of the federal government which they did not like,” McConnell said in remarks on the Senate floor.

Yet weeks later, when the Senate voted on whether to convict Trump of “incitement of insurrection,” , saying that Trump could still be held liable in a court of law.

Trump has since used that vote — in which a majority of Senators, but not the two-thirds majority required for conviction — to argue he cannot be removed from ballots in 2024.

Health concerns

In March of last year, McConnell tripped and fell at a dinner event, suffering a concussion and a fractured rib. He was hospitalized and did not return to the Senate for six weeks.

During a July press conference, and had to be led away by colleagues.

A month later,, hastening calls for the 82-year-old Senator to resign.

“I just had another one of those,” McConnell later quipped about the two freezing up episodes.

Divisions with Trump over Ukraine

Though he continued to lead Republicans in the Senate following those health incidents, his influence . Trump’s grip on the party has strengthened as the Republican presidential primary has played out. While McConnell succeeded in passing a funding bill this month that provides continued financial support to Ukraine for its war against Russia, Trump’s opposition to it has all but doomed it in the House.

Cover photo: AP Photo/Mark Schiefelbein