What does Kyrsten Sinema's party switch mean for the US Senate?

Arizona senator announced a move to the Independent Party

Arizona Senator Kyrsten Sinema on Friday announced a party switch from Democrat to Independent — a move that won't change the balance of power in the Senate, but could affect her political fortunes back home.

Ms Sinema says she won’t caucus with Senate Republicans, so Democrats will still hold the majority next year.

She is expected to continue casting most of her votes with Democrats, while separating herself on certain issues.

“Nothing’s going to change for me,” Ms Sinema declared in a video announcing her decision.

Here's a look at what Ms Sinema’s decision means:

What it means for the US Senate

Democrats will still carry a majority, and day-to-day operations won’t change for Majority Leader Chuck Schumer.

Ms Sinema is still holding her Democratic committee assignments, meaning she can’t upend the party structure too much.

“Kyrsten is independent, that's how she's always been,” Mr Schumer said after her announcement.

“I believe she's a good and effective senator and am looking forward to a productive session in the new Democratic-majority Senate.”

If Ms Sinema votes with Democrats, the party will have a 51-49 majority in the Senate. If she doesn’t, the balance would be 50-49, with Ms Sinema voting as an Independent. Either way, Democrats will have a majority.

What it means for the Democratic agenda

Again, it’s unlikely that Ms Sinema’s move will change the party’s path forward, especially now that Republicans will be in the House majority, and little legislation will move through Congress.

Ms Sinema has always voted in an independent manner — championing some party priorities such as same-sex marriage, which she was instrumental in negotiating before Senate passage last week, and opposing others, such as a minimum wage increase.

She and Democrat Senator Joe Manchin of West Virginia helped water down much of President Joe Biden’s social spending agenda in the first two years of his presidency. She has generally voted for Mr Biden’s executive and judicial nominations.

What it means for her as a senator

What it means for Ms Sinema in Arizona is a trickier question.

Democrats are likely to put up a new candidate and put her in a three-way race for re-election in 2024, if she decides to run again. Voters will decide if they like her independent style, modelled after the late Senator John McCain, or if they would prefer a partisan on the right or left.

“My approach is rare in Washington, and has upset partisans in both parties,” she said.