Democrats are trying to offer counterprograming to the Republican National Convention, announcing $15 million to fund campaign operations in key swing states.

The Democratic National Committee announced Tuesday that it is investing $15 million in state parties, meant to help them open more field offices and bolster staffing.

The investments will pump nearly $2 million into Michigan. The funding will let the state parties add to the 217 existing coordinated campaign offices already employing more than 1,100 staffers in ...