LANSING, Michigan — President Trump on Saturday will, alongside his new running mate, hold in Michigan his first public campaign rally since he was wounded in an assassination attempt.

The joint rally with Senator Vance is the first for the pair since they became the GOP’s nominees at the Republican National Convention at Milwaukee.

Trump kicked off the gathering of Republicans by naming Mr. Vance his vice presidential pick, and concluded it with a speech urging unity following a July 13 shooting in Pennsylvania that left Trump with a bloodied ear and killed one man in the crowd.

“I am running to be president for all of America, not half of America, because there is no victory in winning for half of America,” Trump said Thursday night in what was the longest acceptance speech in modern history at just under 93 minutes.

Michigan is one of the crucial swing states expected to determine the outcome of the presidential election. Trump narrowly won the state by just over 10,000 votes in 2016, but President Biden flipped it back in 2020, winning by a margin of 154,000 votes on his way to the presidency.

With Mr. Vance by his side, Trump will deliver remarks at Grand Rapids, a historically Republican stronghold that has trended increasingly blue in recent elections.

Trump’s choice of Mr. Vance was seen as a move to gain support among so-called Rust Belt voters in places like Michigan, Pennsylvania, Wisconsin, and Ohio who helped Trump notch his surprise 2016 victory.

Mr. Vance specifically mentioned those places during his acceptance speech at the convention, stressing his roots growing up poor in small-town Ohio and pledging not to forget working-class people whose “jobs were sent overseas and children were sent to war.”

Democrats have dominated recent elections in Michigan, but Republicans now see an opening in the state as Democrats are increasingly divided about whether Biden should drop out of the race.

Mr. Biden has insisted he is not quitting, and has attempted to turn the focus back towards Trump, saying Friday that Trump’s acceptance speech at the Republican convention showcased a “dark vision for the future.”

The 81-year-old Democratic incumbent, who appeared in Detroit this month, is currently isolating at his beach home in Delaware after being diagnosed with Covid.

Grand Rapids is the largest city in Kent County, one of three Michigan counties that Trump won in 2016 but Biden flipped in 2020.

It’s also an area where Governor Haley secured a substantial number of votes in the Republican primary in February, a group of voters that both presidential campaigns are now hoping to pick up.