By Will Weissert, Associated Press

WASHINGTON (AP) — President Joe Biden excoriated “MAGA Republicans, the extreme right and Trumpies” on Sept. 5, pitching his Labor Day appeals to union members he hopes will turn out in force for his party in November.

“The middle class built America,” Biden told a workers’ gathering at park grounds in Milwaukee. “Everybody knows that. But unions built the middle class.”

The unofficial start of fall, Labor Day also traditionally starts a political busy season where campaigns scramble to excite voters for Election Day on Nov. 8. That’s when control of the House and Senate, as well some of the country’s top governorships, will be decided.

Trump spoke on Sept. 3 in Wilkes-Barre, near Scranton, where Biden was born. The president made his own Wilkes-Barre trip the previous week to discuss increasing funding for police, decry Republican criticism of the FBI after the raid on Trump’s Florida estate and to argue that new, bipartisan gun measures can help reduce violent crime.

On Sept. 1, Biden went to Independence Hall in Philadelphia for a prime-time address denouncing the “extremism” of Trump’s fiercest supporters.

Trump has endorsed candidates in key races around the country and Biden is warning that some Republicans now believe so strongly in Trumpism that they are willing to undermine core American values to promote it. The president said Thursday that “blind loyalty to a single leader, and a willingness to engage in political violence, is fatal to democracy.”

Trump responded during his Sept. 3 rally that Biden is “an enemy of the state.”

On Sept. 5, Biden said “I’m not talking about all Republicans” but singled out those who have taken Trump’s “Make America Great Again” campaign cry to dangerous or hateful lengths. He highlighted episodes like the Jan. 6, 2021 mob attack on the U.S. Capitol.

Biden told the Milwaukee rally that many in the GOP have “chosen to go backwards, full of anger, violence, hate, division.”

“But together we can, and we must, choose a different path forward,” Biden said. “A future of unity and hope. we’re going to choose to build a better America.”

The crowd jeered as Biden chided Republican Sen. Ron Johnson of Wisconsin for voting against a Democratic-backed measure meant to lower prescription drug prices.

The president also returned to another theme that was a centerpiece of his 2020 campaign, that labor unions boosted the middle class.

Unions endorsements helped Biden overcome disastrous early finishes in Iowa and New Hampshire to win the Democratic primary, and eventually the White House. He has since continued to praise labor unions — even though many voters without college degrees remain among Trump’s strongest bloc of supporters.

Mary Kay Henry, president of the 2-million-member Service Employees International Union, called Biden’s championing of unions heading into the midterms “critical” and said the labor movement must “mobilize in battlegrounds across the country to ensure that working people turn out.”

“We’re really excited about the president speaking directly to workers about, if he had the opportunity, he’d join a union,” Henry said. She added: “This president has signaled which side he’s on. And he’s on the side of working people. And that matters hugely.”

The oldest president in U.S. history has faced speculation about if he’ll seek a second term in 2024 — though Biden has insisted that’s his intention, and the pressure has dissipated some in recent weeks after a string of policy and political successes for him and his party.

With inflation still raging and the president’s approval ratings remaining low, how much Biden can help his party in top races — and how much candidates want him to try — remains to be seen.

That was on display in Wisconsin, where Democratic Lt. Gov. Mandela Barnes is trying to unseat incumbent Sen. Johnson, but did not appear with him in Milwaukee.

In the state’s other top race, Tim Michels, a construction executive endorsed by Trump, is attempting to deny Democratic Gov. Tony Evers a second term. Evers also spoke at the labor event Biden addressed and briefly greeted the president in a backstage photo line.

“We have a president who understands the challenges facing working families,” Evers told the crowd. He said that Biden “hasn’t forgotten that working families matter, not just on Labor Day, but every single day of the year.”

The Wisconsin race could decide which party controls the Senate, while the winner of its governorship may influence results in 2024’s presidential election. The stakes are particularly high given that some Trump-aligned candidates have spread lies about widespread fraud that did not occur during the 2020 election — raising questions about what might happen if a candidate they don’t support wins the next presidential contest.