Inside Michigan's critical swing county

PHOTO: In this file photo, President Donald Trump holds a campaign rally in Macomb County, Michigan, April 28, 2018.PlayJim West/ZUMAPRESS.com via Newscom, FILE
WATCH Key swing district in spotlight ahead of 2020 presidential election

ABC News Live goes on a journey along Route 53 in one of the most critical swing areas in the entire country: Macomb County, Michigan.

The thousands of voters there helped deliver a win for President Donald Trump in the 2016 presidential election. How are these voters feeling nearly three years later? Has the president lived up to his promises? Hear from a mayor who voted for President Trump in 2016, but does not plan to do so again in 2020. He’ll give us the pulse of the independent voters in his city who he says have "motor oil flowing from their veins."

PHOTO: The United Auto Workers union holds a prayer vigil at General Motors Warren Transmission plant to protest the planned closure of the facility, Feb. 22, 2019. Jim West/ZUMAPRESS.com via Newscom
The United Auto Workers union holds a prayer vigil at General Motors' Warren Transmission plant to protest the planned closure of the facility, Feb. 22, 2019.

This all comes just one day before a massive GM assembly plant in Macomb County closes for good.

PHOTO: Congressman Andy Levin speaks as the United Auto Workers union holds a prayer vigil at General Motors Warren Transmission plant to protest the planned closure of the facility, Feb. 22, 2019. Jim West/ZUMAPRESS.com via Newscom
Congressman Andy Levin speaks as the United Auto Workers union holds a prayer vigil at General Motors' Warren Transmission plant to protest the planned closure of the facility, Feb. 22, 2019.

Watch the full segment on a special edition of ABC News Live's "The Briefing Room" live from the 2nd Democratic Debate in Detroit.