Michigan is one of three "blue wall" states that, along with Pennsylvania and Wisconsin, will help decide the election.

Obama will join Harris for a get-out-the-vote event somewhere in Michigan on Oct. 26, according to a senior Harris campaign official who requested anonymity to discuss the event. Oct. 26 is a key date in Michigan because it marks the opening day of statewide early in-person voting.

With three weeks left in the presidential campaign, Democrat Kamala Harris is spending most of her days trying to shore up support in the “blue wall” states of Pennsylvania, Michigan and Wisconsin as

The vice president campaigned at a hockey rink in Erie, Pennsylvania, where she denounced Republican candidate Donald Trump as “unhinged.”

Kamala Harris is spending her week trying to shore up support in the “blue wall” states of Pennsylvania, Michigan and Wisconsin

The Democratic chief executives of the trio of “blue wall” states are on tour, working to whip up excitement for Vice President Kamala Harris’ candidacy (AP video: Mike Householder)

Kamala Harris and Democrats are feverishly working to fortify the “blue wall” states of Wisconsin, Michigan and Pennsylvania, still haunted by Donald Trump’s victories there eight years ago that delivered him the White House and could send him back if he prevails again.