Kyrsten Sinema's party switch may make life that much harder for her already stressed out Hill staff

• Kyrsten Sinema's staff have had a tough time on Capitol Hill, with complaints of a "demoralizing" workplace.
• Last week, the Arizona lawmaker left the Democratic Party.
• It's unlikely her team will now be "the highlight of any Democratic happy hours," said a spokesperson for former Sen. Joe Lieberman.

Sen. Kyrsten Sinema's staff have had a rough go of it on Capitol Hill, with some junior aides to the Arizona lawmaker previously complaining to Insider about having to navigate a "demoralizing" workplace that was routinely flooded with hateful phone calls.

And that's before their boss ditched the Democratic Party last week to become an independent. Democratic lawmakers and colleagues are irked by Sinema's latest rebellion, which is likely to trigger snubs, hostility and awkward encounters for those who work for her, a former Hill staffer told Insider.

"I doubt many Sinema staffers are going to be the highlight of any Democratic happy hours," said Scott Overland, a former spokesperson for then-Sen. Joe Lieberman, who pulled a similar switcheroo in 2006.

The one-time Connecticut Democrat and 2000 vice presidential nominee jumped ship after losing his party's primary. Lieberman registered as an independent, ran for his same seat and won, and spent the latter part of his career rubbing Democratic colleagues the wrong way by palling around with then-Republican Sen. John McCain of Arizona and bad mouthing then-Democratic Sen. Barack Obama of Illinois.

Lieberman's stunning break from the party was too much for Sinema to bear a decade ago. Newly resurfaced video shows her lashing out at Lieberman for disloyalty after Democrats lost their filibuster-proof, 60-vote majority in 2010.

"So what that means is that the Democrats can stop kowtowing to Joe Lieberman and instead seek other avenues," Sinema said in her attempt to relegate Lieberman to political irrelevance.

While Lieberman's decision raised eyebrows, Overland said the by-then 18-year Senate veteran and his staff were probably better suited to handle the repercussions than a freshman lawmaker.

"He (and his staff) built a lot of good relationships with other senators and their staff," Overland wrote of the goodwill Lieberman had earned during his career. "Sen. Sinema has been in office less than one term and has been causing headaches for the party pretty much the entire time."

Still, Overland said he suspects Democratic lawmakers won't go too hard on Sinema to avoid pushing her into the GOP camp. "Given the slim majority, most Dems are going to feign tolerance until we get closer to '24," he told Insider.

A Sinema spokesperson declined to comment for this story.

John LaBombard, Sinema's former communications director, said on Friday that Sinema told her staff about her decision in advance and he had not heard any negative reaction so far. "The folks I talked to feel pretty positive about this," he said.

But Sacha Haworth, Sinema's former campaign communications director, tweeted that her former boss' move is "a slap in the face to everyone who broke their backs to get her elected in 2018."

She's advising the Replace Sinema PAC to hold Sinema accountable and help elect a "true Democrat" to that seat, Haworth told Insider.

"She likes to say that she does everything for Arizonans but it's pretty clear that she does everything for herself and to retain her own relevance, including this latest political calculation of becoming an independent," Haworth said.