After upset Rust Belt victories in the 2016 presidential election, many poll watchers have maintained a close examination of states that Hillary Clinton lost by a slim margin.

President Donald Trump, who has boasted of his strong support from Republicans, appears to be facing an uphill battle in Midwest swing states. According to New York Times/Siena College polls released Monday, Democratic nominee Joe Biden holds a strong lead over Trump in the key battleground states of Wisconsin and Michigan.

In Wisconsin, Biden has a 10-point lead over Trump, 51%-41%. The Wisconsin survey of 789 likely voters was conducted from Oct. 8 to 11, and has a 4-point margin of error. 

Trump defeated Clinton in Wisconsin, which has 10 electoral votes, by a slim 0.77% margin, 47.2%-46.4%.

In Michigan, Biden has an 8-point edge over Trump, 48%- 40%. The Michigan survey of 614 likely voters was conducted from Oct. 6 to Oct. 11, and has a 4.6-point margin of error. Michigan, which has 16 electoral votes, was won by Trump by a 0.23% margin, 47.5%-47.27%.

"Democrats are taking Michigan seriously this time," Rep. Debbie Dingell of Dearborn, Michigan, told CNN.

While Trump trailed in both states in 2016, the polling was much different than in 2020. A Michigan poll from the Detroit News/WDIV in October 2016 showed Clinton leading Trump 42%-31%. But the polls showed the Libertarian nominee at 10% and the Green Party nominee at 4%, while 12% were undecided.

A poll from the Marquette University Law School in October 2016 showed Clinton leading Trump in Wisconsin, 44%-37%, leaving a high percentage undecided or supporting third-party candidates.

The Cook Political Report in 2020 rates both Wisconsin and Michigan as “lean Democrat” in the presidential race. 

If Biden wins Pennsylvania, Wisconsin and Michigan, he has a very strong chance of garnering the 270 electoral votes necessary to seize the White House. A Reuters/Ipsos poll released Monday showed Biden leading Trump by 7 points in Pennsylvania, 51%-44%. 

Ryan Costello, a former Republican congressman in Pennsylvania, told the Philadelphia Inquirer that suburban voters support tougher gun laws and fighting climate change — two issues that could hurt Trump in November.

Recent surveys also show a close race in Ohio, which has 18 electoral votes. Biden recently held events in Toledo and Cincinnati. 

Trump narrowly lost Minnesota and New Hampshire in 2016, though both states have leaned toward Biden in polls. According to Real Clear Politics, Biden has an average lead of 9 points in both states, which have a total of 14 electoral votes.