Kyrsten Sinema leaves Democratic Party, adding drama to tight U.S. Senate margin

U.S. Senator Kyrsten Sinema of Arizona said on Friday she is leaving the Democratic Party and registering as an independent, in an announcement just days after Democrats won a Senate race in Georgia to secure 51 seats in the 100-member chamber.

"Like a lot of Arizonans, I have never fit perfectly in either national party," Sinema said in an article for the Arizona Republic newspaper.

Sinema intends to maintain her committee assignments from the Democrats, an aide told Reuters on condition of anonymity. The aide would not say whether or not Sinema would continue to caucus with Democrats.

Sinema herself, however, said she would not caucus with the Republican Party, according to an interview published by Politico on Friday. If that holds, Democrats could still maintain greater governing control in the closely divided chamber.