Donald Trump will hold a political rally in an indoor arena in Oklahoma next week – his first amid the coronavirus pandemic – prompting organizers to demand attendees sign a waiver that absolves the president’s campaign of any liability from virus-related illnesses. Trump is so keen to return to his cherished campaign format of fronting adoring crowds that he will hold a rally in Tulsa next Friday in the 19,000-seat BOK Center despite the ongoing Covid-19 pandemic. Oklahoma is in the process of reopening businesses, although Governor Kevin Stitt has said people still need to employ social distancing and “minimize time spent in crowded environments”. To overcome this impediment, one that has claimed more than 115,000 lives in the US, the Trump campaign is asking supporters to sign a waiver that makes clear the campaign is not responsible if anyone gets ill from crowding with thousands of others in an enclosed space. By registering to attend, supporters “are acknowledging that an inherent risk of exposure to Covid-19 exists in any public place where people are present”, the waiver states, adding that attendees and guests “voluntarily assume all risks related to exposure to Covid-19” and agree to not hold the Trump campaign, the venue or other organizers liable. Despite the rally breaking the guidelines he has set down, Stitt has welcomed Trump to the state, saying that the event “confirms Oklahoma is the national example in responsibly and safely reopening”. With the US suffering mass joblessness and roiled by anti-racism protests, Trump is attempting to generate momentum for a re-election campaign in which he trails the Democratic challenger Joe Biden in early opinion polls. He should, regardless, still win the electoral college votes of Oklahoma, a solidly Republican-voting state. The rally has already proved controversial, however, because of the site and the date. Tulsa is where a 1921 massacre took place in which a white mob killed up to 300 black people and burned down their buildings. The rally will be held on 19 June, also known as Juneteenth, a holiday that marks the end of slavery in the US. Reacting to the Trump campaign’s choice of location and date for the rally, the California senator Kamala Harris, who is widely tipped to lead Biden’s potential list of vice-presidential candidates, tweeted: “This isn’t just a wink to white supremacists – he’s throwing them a welcome home party.” Hillary Clinton, who lost the 2016 election to Trump, tweeted that: “If your rallies come with a liability waiver, you shouldn’t be holding them.”