National and state Republicans have begun pulling together all of the opposition research done earlier in the cycle, according to a source familiar with the planning, as a large field of Democrats, most of whom ran for House, Senate, or governor this year in Maine, enter the race to replace Platner.That legwork has been accompanied by a flash poll conducted by the National Republican Senatorial Committee, the results of which were shared by its political team in an email to stakeholders on Wednesday. The NRSC said it saw “several risks” with four months until election day, including a “shortened window...