Sarah Jessica Parker Officially Endorses 'Sex and the City' Co-Star Cynthia Nixon Running for NY Governor

Sarah Jessica Parker and Cynthia Nixon attend the 'Divorce' New York premiere  on Oct. 4, 2016.
Getty Images

Cynthia Nixon has Carrie Bradshaw's vote!

Sarah Jessica Parker is supporting her Sex and the City co-star Cynthia Nixon's foray into politics. 

Nixon announced last week that she's running for governor of New York, and on Thursday, Parker officially endorsed her on Instagram. The 53-year-old actress shared a smiling photo of Nixon, calling her a "sister on and off screen."

"@cynthiaenixon A mother," she began her caption. "An activist. An advocate. A fighter. A NY'er. A dear friend. Running for Governor of our great state. My sister on and off screen, you have my love, support and vote. To learn more, read about @cynthiaenixon or donate go to Xx, SJ."

Nixon later responded to the endorsement, writing: "Thank you @SJP, it means so much."

On Wednesday, it appeared Parker was still not 100 percent on board with Nixon's campaign. “Cynthia has been my friend and colleague since we were little girls," she told Page Six in a statement through her spokeswoman. "I look forward to talking to her about her New York state gubernatorial bid.”

Meanwhile, fellow SATC star Kristin Davis had already enthusiastically tweeted about Nixon's run.

However, SATC star Kim Cattrall was notably more measured in her support.

ET spoke with 51-year-old Nixon while she was en route to her first campaign event in Brooklyn, New York, last Tuesday. 

"This is a decision that has been a longtime coming," she said of her decision to challenge Democratic Gov. Andrew Cuomo in the state's Democratic primary in September.  "People have actually been asking me to do this for nine years."

Nixon also revealed whether the nixing of the third SATC movie had any impact on her decision to run for office. Here's her response: