ASHEBORO, United States (AFP)— Donald Trump will be behind bulletproof glass Wednesday for his first outdoor rally since surviving an assassination attempt, but the Republican faces a bigger challenge in matching the white-hot enthusiasm of crowds flocking to Kamala Harris.

The event in Asheboro, North Carolina, a battleground state in the tight November 5 election, is a chance for Trump to reclaim his longtime dominance in staging spectacular rallies.

Accompanied by vice presidential pick J.D. Vance, he will take to the stage at an aviation museum, speaking against a backdrop of vintage war planes about his national security policies.

It is the first time he will hold a big event outdoors since being lightly injured in an attempted assassination at a similarly open site in Butler, Pennsylvania, a month ago. That attack left one bystander dead before the shooter was killed in return fire by a Secret Service sniper.

The Secret Service recommended that Trump, 78, stick to more easily controllable indoor venues, such as sports arenas. He has since attended about a dozen indoor events.

The Secret Service does not comment publicly on security operations and did not respond to requests for comment on Wednesday’s preparations. However, a screen could clearly be seen being erected around the stage Trump and Vance will speak from later.

Crowds are an integral part of Trump’s political brand in which the right-wing billionaire seeks to portray himself as an outsider and man of the people. Even as president he kept up a steady schedule of election-style rallies, often filling sports arenas with at least 10,000 people.

He’d counted on these demonstrations of strength as a key weapon in his plan to make President Joe Biden, whose own public events are generally low-key and relatively small affairs, look ineffectual.

Trump’s strategy was upended on July 21, however, when Biden, 81, abruptly dropped his reelection bid and endorsed his younger vice president as the future of the Democratic Party.

The immediate explosion of Democratic support for Harris has stunned the Trump campaign.

And nowhere is the shift in momentum more visible than in the 59-year-old Harris’s ability to pack arenas.

She is consistently filling venues with well over 10,000. On Tuesday night supporters packed the Democratic National Convention in Chicago while she hosted a mass rally of her own in Milwaukee.

In a clear dig at Trump, her Milwaukee event took place in exactly the same arena that the Republicans had used for their convention back in July.

North Carolina is one of a handful of swing states that are expected to determine the outcome of the November 5 election.

US presidential elections are not decided by an overall national vote but state-by-state, with each state worth varying amounts of Electoral College votes, and the winning candidate needing to score the majority.

Most states trend solidly Republican or firmly Democrat, and only around seven are considered true toss-ups where the race is really fought — and where the candidates spend most of their campaign.