A former Obamacare marketplace worker from St. Louis County says she will challenge Sen. Claire McCaskill for Missouri's Democratic Senate nomination next year, on grounds that the incumbent is too conservative on health care and other issues.

Angelica Earl, 31, a recently laid-off verification specialist for insurance applicants under the Affordable Care Act, lives near Overland.

She said Wednesday she opposes McCaskill's call for bipartisan fixes to the current ACA because it doesn't go far enough. "My stance is single-payer health care for all," Earl said.

She said she plans to soon file papers opening a campaign committee for the seat.

Earl, who has no previous elective experience, is the first Democrat to announce she will attempt to win the party's nomination over McCaskill, who is seeking her third term.

There is a wide field of announced and potential Republican candidates eyeing the GOP nomination.

The 2018 primaries are on Aug. 7, with a candidate filing deadline of March 27.

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