The retirement of U.S. Senator Kyrsten S. Sinema on Tuesday marks the end of an impressive political career which broke down barriers, stood at the forefront and raised many eyebrows.

Sinema (I-Ariz.) joined the Senate in 2018 after three terms as a member of the U.S. House of Representatives. He also spent many years in the Arizona Legislature, where he was active in politics at the state level.

Sinema has been involved in 10 memorable moments.

Win the 2018 Senate Race

The last time a Democrat from Arizona won a U.S. Senate election was in 1998, when Vice President George H.W. Bush defeated Massachusetts Governor. Michael Dukakis wins the White House.

It was the night that Sen. Dennis DeConcini (D-Ariz.) won his last term.

It took Sinema thirty years to break a nine-year losing streak for her party.

Sinema won in 2018 amid an historic “blue-wave”, making it appear fated.

The wave that year in Washington was confined to the House of Representatives. In those elections, Republicans won two Senate seats in the United States. Sinema’s victory in a traditionally-red state also limited their gains.

Her victory in Arizona marked a shift to the left, where Democrats enjoyed their greatest success in years.

Marriage equality legislation passed in 2006

In 2006, Arizona voters were the first to reject a national ban on gay marriage.

Sinema was a co-chair of that effort, and helped to set up the strategy where heterosexual couples and unmarried partners were told about how Proposition 107 can erase their rights too.

The strategy was successful and it rejected the “lose forward” mentality, in which gays assumed that a series losses would build goodwill over time to change public opinion.

The victory was not as grand as it seemed.

Arizona’s law continues to prohibit gay marriage. Two years later, as many gay supporters feared, an even more narrowly-focused measure to ban gay marriage was easily passed in the state constitution.

Proposition 107 had a second bit of history as well: Sinema fired Ruben Gallego her campaign manager, who is now running for her Senate seat.

They both benefited from their efforts in promoting the ballot measure.

In 2022, you can quit the Democratic Party.

Sinema was a political powerhouse by 2022. She seemed to be the pivot on which the Senate majority rests.

In the process, she also shattered her Democratic support.

Her former supporters saw her unrelenting defense of the legislative filibuster as a greenlighting of obstructionist politics which sabotaged President Joe Biden’s agenda.

Sinema, who announced her independence in The Arizona Republic two days after Democrats had won the Georgia runoff in order to create some breathing room in the Senate.

It was not only a move that caused new concerns for Democrats but also hastened her political decline.

Sinema was facing a probable Democratic primary at that point, as well as the anger of her base who wanted to dismiss her.

Gallego was quickly chosen by Democrats over Sinema in polls. Sinema was left as influential as ever in Senate, but she became politically orphaned.

No longer seeking Senate re-election in 2024

Sinema’s video announcement Tuesday confirmed that her political troubles were not over.

In her message, she blamed the unwillingness of members of Congress to compromise on the public and praised them for it. She reaffirmed specifically her belief in the deal-making method she uses.

Sinema did not acknowledge the criticisms that have been leveled at her in recent times.

Sinema was the subject of a number of complaints alleging lavish spending on her campaign budget and office budget.

Democrats wanted someone who was more loyal to their party.

Republicans wanted a Republican. Independents, despite their affiliations, want someone from the two major political parties.

Sinema’s idea was unique in that there had never been a similar third-party run. It’s because, like Sinema, other politicians realized that it would not work.

A viral 2021

Sinema was known as a serious legislator who worked to find bipartisan agreement.

She was also known for her viral moments, which heightened the opposition from her critics.

Three episodes in 2021, specifically, galvanized anti-Sinema forces.

She delivered a memorable thumbs down in March on a provision that would have raised the federal minimum wage through a bill to relieve coronavirus. Her office claimed that she did so to thank the Senate staffers who had been rewarded with a cake for a marathon work session.

Her critics criticized her for being flippant about a crucial economic issue.

Sinema posted a picture on social media a few weeks later showing her drinking sangria while wearing pink newsboy glasses and a ring with the words, “F– off.” It was a very obvious post.

Sinema didn’t make it clear to whom she was referring. Her critics assumed it was them.

In October, immigration activists confronted Sinema and recorded an incident where they encouraged her to support the domestic agenda of President Joe Biden. They also followed her in a women’s bathroom at Arizona State University.

The moments on their own should not have been crucial. As a group, they reveal that Sinema lost the support of many people who helped her win the election.

Her border security bill for 2024 is a failure

Sinema’s fundraising for her campaign dipped throughout 2023, and the polling data on the Senate race showed that she was in a distant third place. Sinema’s campaign fundraising dipped throughout 2023 and her standing in the limited polling on the Senate race made it clear that she was a distant third.

Sinema’s bill had bipartisan support. The bill addressed a major issue that many others thought was insoluble. Biden supported it. It took months to negotiate.

It was possible, if that measure had found traction in Congress — and especially with the Republicans Sinema hoped to reach over the past months — to use that bill as a way to convince them that Sinema possessed the special ability to break the Washington gridlock.

Former President Donald Trump instead urged Republicans not to pass the bill, and this vaporized all of her hard work, or at least any chance she had of running for another term.

Sinema gave media interviews infrequently, but a few were conducted ahead of the bill’s release.

She didn’t criticize her colleagues for votes or other issues. Sinema’s uncharacteristic outburst came as her border-security bill was defeated by the filibuster.

Sinema stated on the Senate floor that “less than 24 hours after the bill was released, my Republican colleagues have changed their minds.” It turns out that they only want to talk, and not take any action. As it turns out, border security isn’t actually a thing.