Democratic presidential candidate former Vice President Joe Biden speaks Wednesday, Sept. 16, 2020, in Wilmington, Del. Biden generated headlines in February with a debate-stage promise to name the first Black female Supreme Court justice if he wins the White House. Since then, the Democratic presidential nominee has said little about the court. He's resisted calls from President Donald Trump, Republicans and even some Democrats to release a list of potential nominee.

DULUTH, Minn. — A solidly blue state for the past half century, Minnesota became an unquestioned presidential battleground on Friday as President Donald Trump and Democratic challenger Joe Biden fought for working-class voters in dueling events that marked the beginning of early voting.

Their contrasting styles and stances during the day and evening gave fresh signs of the campaign to come in the final weeks before Election Day.

The candidates steered clear of the state’s most populated areas near Minneapolis to focus on blue-collar voters, some of whom shifted to Republicans for the first time in 2016. Trump went to Bemidji, about 200 miles (320 kilometers) north of Minneapolis, while Biden campaigned in a suburb of Duluth, on the banks of Lake Superior and close to the Wisconsin border.

Biden railed against Trump’s inability to control the pandemic, casting the president’s reluctance to embrace more serious social distancing safeguards as “negligence and selfishness” that cost American lives. Trump, before leaving the White House, said as he has many times that “we’ve done a phenomenal job” against the virus and predicted mass vaccinations by spring.

Biden, at a carpenter union’s training hall in Minnesota, emphasized his plans to boost American manufacturing.

“It’s time to reward hard work in America and not wealth,” Biden declared with roughly a dozen workers looking on.

Trump, meanwhile, predicted victory in Minnesota in November despite the state’s long history of backing Democratic candidates.

“Forty-six days from now we’re going to win Minnesota and we’re going to win four more years in the White House,” Trump told thousands of supporters at the regional airport in Bemidji.

Since narrowly losing Minnesota in 2016, Trump has emphasized the state in hopes that a victory this year could offset losses in other states. He has visited regularly and kept a close eye on issues of particular importance to rural corners of the state. He’s reversed an Obama administration policy prohibiting the development of copper-nickel mining and has bailed out soybean, corn and other farmers who have been hurt by trade clashes with China.