Oct. 11 (UPI) -- Maine Gov. Janet Mills is expected to launch a campaign on Tuesday to unseat longtime U.S. Susan Collins, R-ME, according to internal campaign documents and a now-deleted social media post. According to a campaign document first reported by Axios and since confirmed by several other news organizations, Mills plans to join the Democrat primary field for Collins' seat next year, as she is term-limited and cannot run for re-election as governor. Democrats have been recruiting