Update (9/28): Kyrsten Sinema has officially announced that she will run for Senate. You can watch the campaign announcement here.

Original post from September 18 continues below:

Any day now, we should be getting the official announcement: Kyrsten Sinema is running for Jeff Flake's Senate seat.

The congresswoman from District 9, who is ostensibly a Democrat, has raised over $3.2 million so far. And she's got the support of the Democratic establishment: The Hill reports that Senate Minority Leader Chuck Schumer is backing her over other potential primary candidates, including Phoenix Mayor Greg Stanton.

The latest polling numbers show Sinema leading Flake by eight points, which naturally has a lot of people excited at the prospect of flipping a seat that's been held by Republicans for decades — in a red state, no less. But if you were looking forward to backing a genuinely progressive candidate who supports single-payer health care and fights back against the constant demonization of immigrants and refugees, Kyrsten Sinema leaves a lot to be desired.

It's also unclear how much her presence in the Senate would actually help Democrats. FiveThirtyEight calculates her "Trump score" at 48.8 percent, meaning her votes align with President Donald Trump's position nearly half the time. Only two other Democrats in Congress voted with the president more frequently.

Let's take a look at her voting record over the past year:

• In May, she voted to pass the Thin Blue Line Act, which makes it easier for prosecutors to seek the death penalty for people who kill, or attempt to kill, first responders. (Todd Cox, the policy director for the NAACP Legal Defense and Education Fund, has written extensively about why this kind of legislation is so counterproductive.)

• In June, she voted for the Verify First Act, a bill designed to prevent people from accessing health care through the Affordable Care Act until their citizenship status had been verified. Other Democrats in Congress, such as Texas' Beto O'Rourke, warned that it would just end up making it take that much longer for people in need — especially newly arrived immigrants — to get health insurance.

• In July, she not only supported the anti-immigrant garbage known as "Kate's Law," but also voted in favor of the Make America Secure Appropriations Act, which included $1.6 billion in funding for the border wall.

• Then, just this past week, she joined Republicans in voting for the Criminal Alien Gang Member Removal Act, which the ACLU warns will give the Trump administration the ability to detain and deport non-citizens solely because they live in an immigrant neighborhood considered to be "gang-affiliated." (MALDEF described the bill as being "in keeping with the very worst traditions in nativist lawmaking.")

• She's also one of the co-sponsors of HR 620, which disability-rights advocates warn would weaken the Americans with Disabilities Act by removing incentives for businesses to comply with the law.

Throwing people under the bus in the name of bipartisanship, unfortunately, is nothing new for Sinema. In 2015, she voted to prevent Syrian and Iraqi refugees from being resettled in the United States until tighter vetting processes could be be put in place — despite the fact that the process already took two years, and experts warned that adding new regulations would effectively shut it down altogether.

That same year, she introduced legislation aimed at cracking down on the U.S. visa waiver program and was one of only six Democrats to vote to punish sanctuary cities. And she joined Republicans in passing bills intended to deregulate the banking industry and attack the Affordable Care Act's employer mandate.

.@RepSinema a picture is worth a thousand words but the only word we have is: shameful pic.twitter.com/NzinLmKeGw — ProgressNow Arizona (@ProgressNowAZ) September 14, 2017

None of this is to say that Sinema wouldn't be a better choice for progressives than Jeff Flake or Kelli Ward. Sinema is pro-choice and has a decent record on environmental issues, resulting in a B+ score from the League of Conservation Voters. She supports the DREAM Act, which is about the bare minimum that you can expect from anyone calling themselves a Democrat these days.

And there's no question that Sinema has an impressive life story. A high school valedictorian who graduated at 16, she grew up poor, living in an abandoned gas station in Florida with no running water for two years. She went on to become a social worker and earn a law degree and a Ph.D. She jettisoned the Mormon faith that she was brought up in, and embraced her bisexuality. As an unmarried, childless woman in Congress, she's basically a unicorn.

Still, that doesn't exempt her from criticism, and Sinema has already pissed off a lot of people by arguing that it's unrealistic to campaign on promises of single-payer health care and free college. Plus, as political commenter Adriana Maestas recently pointed out, it's hard to imagine that running a candidate who's voted with the GOP on anti-immigrant bills will do much to improve Latino voter turnout.

Here's Dem @RepSinema supporting a Balanced Budget Amendment that would destroy every social program in the country; Medicare to Medicaid https://t.co/nhwqGUuGC2 — connor (@c_boy17) July 17, 2017

Ironically, Sinema was once criticized for being too far to the left. When she first ran for the Arizona Legislature in 2002, she was deemed "too extreme" by the Arizona Democratic Party. (She ended up running as an independent instead.)

By then, she'd already made a name for herself as an anti-war protester who'd worked on Ralph Nader's 2000 presidential campaign. In a candidate questionnaire, she decried "our country's trend of expanding and increasing militarization" and wrote that she'd support closing Luke Air Force Base.

That same year, in a letter to the editor published in the Arizona Republic, she wrote, "Until the average American realizes that capitalism damages her livelihood while augmenting the livelihoods of the wealthy, the Almighty Dollar will continue to rule. It certainly is not ruling in our favor." An editor aptly titled it "Capitalism Damaging."

In 2004, Sinema ran as a Democrat and won. As a state legislator, she fought to block a ban on same-sex marriage, marched for immigrants' rights, and spoke up against attacks on reproductive freedom. In fact, we here at Phoenix New Times named her "Best Local Lefty Icon" in 2011.

Not to say that she was perfect — she veered into nativist territory when she introduced legislation intended to result in harsher penalties for the operators of drop houses, despite the fact that state law already criminalized anyone who so much as gave an undocumented immigrant a ride to the grocery store. And then there was that time she declared, "I love Russell!" — referring to Russell Pearce, the original sponsor of SB 1070.

GovTrack's analysis of Sinema's votes puts her squarely in the center. Govtrack.us

In order to win a Congressional seat in a district with a mix of Democrats and Republicans, Sinema had to strategically rebrand herself a centrist, political analysts have pointed out. She did so successfully, beating her Republican opponent in 2012, and then quickly developing a reputation for being willing to work on both sides of the aisle.

That's unlikely to change if she runs for Senate. Perhaps the best preview of what a Kyrsten Sinema 2018 campaign would look like comes from a New York Times story published in August:

Ms. Sinema said a Democrat would have to campaign in a virtually nonpartisan way to win a Senate race, and she criticized national Democrats for moving too far to the left. She described liberal promises of free college and single-payer health care as “just not real.” “It’s irresponsible to promise a platform that you can’t deliver on,’’ she said. “You’re not going to get free college.”

Cue the inevitable arguments about "purity tests," whether there's still a place for bipartisan compromise in politics, why Democrats keep pushing centrist candidates, and so on. We're tired already.