CHICAGO — While much of the news coverage has centered on the race for the White House and which party will control Washington, Democrats are plotting an overlooked but aggressive campaign to reshape the power dynamics in state capitals across the country. 

Republicans control 57 legislative chambers, while Democrats have majorities in 41. Both sides are waging battles for legislative control in states like Arizona, Pennsylvania, Michigan, and Wisconsin, where just a handful of races could make a difference. And they are putting millions of dollars behind their efforts.