Sinema Stands Apart From Most Recent Senate Party-Switchers

Kyrsten Sinema may be the first senator to pretend she’s a Party of One.
Photo: Kent Nishimura/Los Angeles Times via Getty Images

Arizona senator Kyrsten Sinema’s recent announcement that she would henceforth identify as an independent rather than as a Democrat was a reminder that all very fragile congressional majorities are vulnerable to blackmail from restive or opportunistic members. Sinema is not in the catbird seat she would have occupied had Senator Raphael Warnock lost his general election runoff, making the Democratic Senate majority depend on the loyalty of all 50 senators. And as my colleague Jonathan Chait pointed out, her gambit probably had more to do with raising her 2024 reelection prospects than giving her more leverage in the Senate.

But in understanding where Sinema fits into the contemporary Senate scene, it helps to take a look at other Senate party-switchers in the recent past. As it happens, she’s the fourth senator since 2006 to announce she would be an independent caucusing with Democrats. And they’re a mixed bag.

In 2006, two independents were elected to the Senate and chose to participate in the Democratic caucus, which had just taken over control of the chamber. Neither were new figures. One, Bernie Sanders of Vermont, had a long history of being a progressive independent (and self-identified “democratic socialist”) and kept that status during eight terms in the House. So it was no surprise he continued that status in the Senate (though he did, for legal reasons, briefly self-identify as a Democrat during his unsuccessful presidential campaign of 2020).

Joe Lieberman was a different matter. A Democratic senator from Connecticut dating back to 1988, and the 2000 Democratic vice-presidential candidate, Lieberman battled often with progressives and lost the Democratic Senate nomination to Ned Lamont (now governor of Connecticut). But Lieberman won the general election as an independent. Partly out of pique at the Democrats who didn’t support him, Lieberman remained independent during his last term in the Senate, though he continued to caucus with Democrats as he always had. There was some talk of Lieberman becoming a Republican, but it subsided after GOP leaders vetoed the idea of making Lieberman his friend John McCain’s running mate in 2008.

Just as Lieberman left the Senate, another New England independent caucusing with Democrats arrived: former Maine governor Angus King. Maine had a rich tradition of viable independent and minor-party elected officials, and King was elected governor as an independent in 1994, then reelected in 1998. So no one was terribly surprised when he later ran as an independent for the Senate in 2012. He immediately announced plans to caucus with Senate Democrats and hasn’t revisited that decision publicly.

Sinema has now joined Sanders and King as independents who caucus with Senate Democrats. Aside from her deliberate positioning as someone willing to break party ranks and vote with Republicans, the main thing that distinguishes the Arizonan from the rest of the group is the low esteem in which she’s held back home. She does not, moreover, come from a state with any long-standing tradition of independent candidates. Which makes you wonder how long her independence will last.

There have certainly been other temporary independents in the Senate. One was New Hampshire senator Bob Smith, a hard-core conservative Republican known for joining Jesse Helms in battles against gay rights. In 1999, after three terms in the House and into his second term in the Senate, Smith launched a misguided 2000 presidential campaign. When that predictably went nowhere, he announced he was leaving the GOP to pursue the presidential nomination of the right-wing Taxpayers Party. When that didn’t work out, he called himself an independent for a while before endorsing George W. Bush’s candidacy. He later fully rejoined the GOP in order to assume a key committee chairmanship. But in 2002, mostly because of his erratic sense of party loyalty, Smith lost a Senate primary to John E. Sununu, son of former White House chief of staff John H. Sununu and brother of current New Hampshire Governor Chris Sununu. He moved to Florida to begin a new career in real estate. It’s possible Sinema is headed for a change of scenery or career.

Sinema really isn’t much like the most common Senate Democrats who left their party. At lower levels of elected office, there was a big wave of conservative (mostly southern) Democrats beginning in the 1960s who defected from the party after its firm commitment to civil rights, mostly migrating directly into a newly friendly GOP. Three U.S. senators who fit that pattern of ideological sorting-out were pretty serious figures: (1) South Carolina’s Strom Thurmond, the 1948 Dixiecrat presidential candidate who flipped in 1964 as his fellow segregationists backed Barry Goldwater; (2) Virginia’s Harry Byrd Jr., the scion of a famous conservative Democratic machine who became an independent in 1970 but still caucused with Democrats while voting mostly with Republicans; and (3) Alabama’s Richard Shelby, who followed his voters who flipped to the GOP after Republicans swept southern elections while retaking control of Congress in 1994.

All these party-flippers followed as much as led their voters. Sinema is not following any discernible bloc of voters, for all the talk about her representing people disgusted with both parties. The actual Arizonans voting for pols in both parties are less than enchanted with her.

Sinema also really isn’t like the two Republican party-switchers who moved left in recent years, though they did share her opportunistic timing.

In 2001, Vermont’s Jim Jeffords, reportedly upset about George W. Bush’s opposition to the Individuals With Disabilities Education Act, abandoned the GOP after a quarter-century of congressional service to become an independent caucusing with Democrats. This flipped control of the chamber briefly (Republicans won back the Senate in 2002).

In 2009, longtime Republican senator Arlen Specter of Pennsylvania was facing a tough reelection primary challenge from a conservative he had barely defeated in 2004, Pat Toomey (who is himself retiring from the Senate this year). GOP activists were particularly angry at Specter for supporting Barack Obama’s economic-stimulus package. So he doubled down and flipped parties, just in time to give Democrats the Senate super-majority they needed to pass the Affordable Care Act. Specter subsequently lost a 2010 Democratic primary to Joe Sestak, and succumbed to non-Hodgkin’s lymphoma in 2012. Democrats lost their Senate supermajority in a 2010 special election in Massachusetts.

All in all, Kyrsten Sinema is a tactical party-switcher without the clear ideological motives of many senators who moved from one party to the other, or even the clear tactical motives that have led predecessors to seek leverage by moving to an independent position between the two parties. Right now, she represents mostly her very own self — a party of one.