LANSING, Mich. (AP) — Democratic Sen. Gary Peters and Republican challenger John James are making their final cases to the electorate in the closing days of a $100 million-plus duel that will help shape whether the winner of the presidential race can enact his legislative agenda.

Michigan, long a presidential battleground, is also a key Senate battleground in 2020.

Peters, the only non-incumbent Democrat to claim a Senate seat in 2014, is one of just two Senate Democrats running in a state Donald Trump won four years ago. Public polls have shown him extending his lead over James, a Black businessman and Iraq War veteran, but Republicans who see an opening insist James has a shot. Trump has trailed Democrat Joe Biden at the top of the ticket.

“We see a potential opportunity,” said Steven Law, president of the Senate Leadership Fund, a super PAC that put an additional $4.6 million into Michigan this weekend to support James. "We think the numbers are moving rapidly.”

The Peters camp remains confident, however, pointing to stable polling and his appeal among female and independent voters. He continues to highlight his bipartisan legislative accomplishments while also stating the stakes — warning that Republicans have no plan to replace the federal health care law if the Supreme Court throws it out as requested by the Trump administration during the coronavirus pandemic.

“We have a real shot to take the majority in the Senate. But we have to hold Michigan,” he said Thursday in East Lansing, where he joined Jill Biden for a canvassing launch with educators. “The Senate is so important to making sure Joe Biden and Kamala Harris are successful.”

While courting Black voters in Detroit a day earlier, a fired-up Peters, 61, pointed to James' appearance at a Trump rally in Lansing and said James has backed Trump “2,000%" — a comment James made in 2017 during a GOP primary. He has accused James of hiding from policy issues and relying on “shallow talking points.”

James, 39, on Thursday campaigned with former U.N. Ambassador Nikki Haley in Novi. He called Peters an “invisible man” who skips committee meetings and a “gaslighter” who is a reliable vote for liberal policies.

He said Michigan is a “purple state” and lobbied for “balance” since Michigan's other senator, Debbie Stabenow, is a Democrat. “Both parties have failed,” he said, saying the GOP is far from perfect but its platform most closely aligns with his economic and moral values because leftists cannot be trusted.

He highlighted his experience flying Army helicopters in combat and leading an automotive logistics company founded by his father. Peters also is a veteran, having served in the Navy Reserve.

“I believe our time is now,” James said.

He aims to be the first Michigan Republican to win a Senate seat in a quarter-century. The candidates and allied groups have spent $130 million on TV, digital and radio ads — eighth-most among Senate contests, according to data from the ad tracking firm Kantar/CMAG. Democrats have poured $13 million more into advertising than Republicans have. James, unlike other Republican Senate candidates, has largely kept pace in fundraising with his opponent.

In a closing ad, Peters is joined by his wife, who says her problem-solving husband will “take on anyone” because it is personal for him. He pledges to protect people with preexisting conditions, lower drug prices and strengthen manufacturing.

James' final ad is a bid for unity amid political polarization, with the narrator — actor Tim Allen, who voices “Pure Michigan” tourism ads — highlighting James' life experience and his charity work.

Experts say the result likely will be tied in large part to the presidential race, where Biden appears to be well-positioned barring a late Trump surge.

John Sellek, a GOP strategist, said Trump — who is campaigning frequently here in the final stretch — would have to narrow the margin to 4 percentage points by expanding the universe of blue-collar and rural voters, reversing his standing with seniors and turning the tide in conservative western Michigan with the recent appointment of Amy Coney Barrett to the Supreme Court.

Peters planned to join Biden and former President Barack Obama at events in the Democratic strongholds of Detroit and Flint on Saturday.

“There is most definitely a path for James as he will likely run ahead of Trump by establishing his own presence as a candidate, but Biden is making it tougher by bringing in Obama to excite the Black vote in a way Peters failed to do,” Sellek said.

But Lon Johnson, a former chairman of the Michigan Democratic Party, said it will be difficult for James to outperform his party’s standard-bearer, whose showdown with Biden has become a referendum on the president, by more than 1 or 2 points.

“He's still running an uphill race here," he said. “There’s just not a path.”

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Associated Press writer Lisa Mascaro in Washington contributed to this report.

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