Just days after the Democrats secured a 51-49 Senate with Sen. Raphael Warnock’s win in Georgia, Sinema made waves by announcing her departure from the party to register as an independent instead. Then, on Monday, Manchin left the door open to ditching the party in the future, telling reporters: “I’m not a Washington Democrat, I don’t know what to tell you.”
“I’ll look at all of these things. I’ve always looked at all those things, but I have no intention of doing anything right now. Whether I do something later, I can’t tell you what the future is going to bring.”
However, Manchin isn’t the only blue senator who could make President Joe Biden’s life difficult in the coming two years. Here is a look at the four other senators who have shown an inclination to buck party lines at times and not vote in lockstep with Biden.
Jon Tester (D-MT)
Second only to Manchin, who votes with Biden 87.9% of the time, per FiveThirtyEight, Tester is another rare Democrat from a deep blue state. Although he recently declined to commit to vie for reelection in 2024, Tester will have at least another two years in the upper chamber.
A moderate who crows about bipartisanship, Tester has called for boosting energy output and previously joined Republicans in backing the rollback of Dodd-Frank banking regulations during the Trump administration. He is considered among the least liberal members of the Democratic Senate caucus and has voted with Biden 89.8% of the time — less than Sinema at 93.1%.
Bernie Sanders (I-VT)
After nearly edging out Biden in the 2020 presidential primary, the independent Vermont senator and self-described socialist has emerged as a frequent progressive dissenter to Biden in the upper chamber. Having voted with Biden 91.4% of the time, he recently opposed Biden’s efforts to stave off a looming railroad union strike, bashing the deal for not incorporating paid sick leave for workers.
Sanders has also opposed the sale of weapons to Saudi Arabia and the nomination of Thomas Vilsack to be secretary of agriculture. He has not ruled out a 2024 run for the presidency.
Jacky Rosen (D-NV)
Hailing from the bellwether state of Nevada, Rosen generally hews close to the middle of the Democratic Senate caucus on the ideological spectrum. During the past two years, she has bucked the Biden administration on a handful of COVID-19 suppression measures, which have hit hard at home in the Battle Born State, known for its service industry.
She sided with Republicans in voting disapproval of the mask mandate for public transportation and in Head Start programs. More recently, she backed a measure to declare an end to the COVID-19 national emergency.
Aside from pandemic policies, perhaps her most notable defiance has been opposition to a waiver to allow Lloyd Austin to become secretary of defense to forgo the waiting period for former active-duty military personnel to serve such a role. Rosen has voted with Biden 91.5% of the time and is up for reelection in 2024.
Catherine Cortez Masto (D-NV)
Cortez Masto played a pivotal role in helping the Democrats get to 51 seats when she defeated Adam Laxalt in the midterm elections. Her record is almost identical to her colleague Rosen with a 91.5% voting record for Biden’s policies. Like Rosen, most of Cortez Masto’s defiance stemmed from COVID-19 policies, which ravaged Nevada’s service sector and has been credited for making her 2022 reelection bid so challenging.
She also voted against the waiver for Austin.
Perhaps the greatest congressional threat to Biden’s domestic agenda will come from the House, which has a threadbare Republican majority. Internal party defiance in the Senate could weaken the Biden administration’s leverage in negotiations with Republicans or hamper key nominees.