Outside, traders were braving the bitter cold to sell Trump hats, T-shirts and other merchandise. Inside, hundreds of Trump supporters were proudly sporting “Make America great again” (Maga) regalia. They were surrounded by big screens, loudspeakers, TV cameras, patriotic flags and “Team Trump” logos.It had all the trappings of a Donald Trump campaign rally but one thing was missing: Donald Trump.The former US president was content to let South Dakota’s governor, Kristi Noem, speak on his behalf at the convention centre in Sioux City, Iowa, on Wednesday night. “We would never have the situation going on like we see in the Middle East right now,” Noem said. “If he had been in the White House, we would never see what was going on with Russia and Ukraine.”It was not the first time that Trump has delegated his campaign to a proxy ahead of the Iowa caucuses on 15 January, the first of the state-by-state contests in which Republicans choose a presidential nominee to take on Democrat Joe Biden in November’s election.While rivals Ron DeSantis and Nikki Haley have crisscrossed Iowa in search of votes, the frontrunner has been content to stay at home and let allies do much of the legwork for him. For these campaign surrogates, it is a very public opportunity to stake their claim to a job in a future Trump cabinet – or even as his vice-president.This week’s lineup included Ben Carson, a former housing secretary seeking to rally Iowa’s Christian evangelical voters; Marjorie Taylor Greene, a far-right firebrand and prominent ally of Trump in Congress; and Eric Trump, a son of the former president who followed him into business.On Monday two “Team Trump Iowa Faith Events” will feature ex-White House press secretary Sarah Huckabee Sanders, now governor of Arkansas, and her father, Mike Huckabee, a former governor of the same state.Other prominent proxies include Florida congressmen Byron Donalds and Matt Gaetz; Kari Lake, a former candidate for Arizona governor who has roots in Iowa; Iowa’s attorney general, Brenna Bird, whose endorsement of Trump put her at odds with the state’s governor, Kim Reynolds, a backer of DeSantis; and actor Roseanne Barr, who five years ago was fired from her sitcom, Roseanne, after posting a racist tweet.For the Trump campaign, these events are useful to scoop up personal information that allows for follow-up calls and texts to remind supporters to show up at the caucuses. For the surrogates, they represent a chance to enhance political careers or boost their profile in the “Maga universe”, which might lead to work as a host or pundit in rightwing media.Kurt Bardella, a Democratic strategist, said: “It’s a live audition, using the campaign trail as a substitute for the boardroom set that he had on The Apprentice. All of these people are jockeying and trying to curry favour with Trump so that they are considered to be on the shortlist for some of the high-visibility positions that might become available if he were to win.”Since 2016, Trump campaigns have also been a family affair. His eldest son, Don Jr, attended the first Republican primary debate in Milwaukee along his girlfriend, Kimberly Guilfoyle, but they were denied access to the official “spin room” so talked to reporters on the sidelines. Trump’s daughter Ivanka, a former senior adviser at the White House, is sitting this one out.Eric Trump, who turns 40 on Saturday , has long been mocked by comedians and satirists as the poor relation but seems to be working doubly hard to impress his dad. He told an audience in Ankeny, Iowa, on Thursday: “The greatest fighter in the world is my father. In fact, it’s kind of sometimes what he’s actually criticised for.”Bardella, a former senior adviser for Republicans on the House oversight committee, added: “It’s ‘I’m trying to win your approval’, whether it’s politically in terms of someone like Kristi Noem particularly or the lifelong pursuit of Eric Trump and Donald Trump Jr to live up to the last name, to the outsized shadow that their father cast over their lives.”Such ostentatious displays of fealty could prove valuable to Trump in a year in which he faces the distraction of four criminal cases that threaten to strand him in a courtroom instead of the campaign trail. He is expected to appear at a federal appeals court hearing next week regarding the scope of his presidential immunity while in office.He must also choose a running mate. It is safe to assume that it will not be Mike Pence, his former vice-president, who alienated Trump by certifying the 2020 election results and ran an abortive campaign against him last year. Potential contenders include Haley, Lake and Noem as well as Senator Tim Scott of South Carolina, Representative Elise Stefanik of New York, entrepreneur and 2024 candidate Vivek Ramaswamy, and former Fox News host Tucker Carlson.skip past newsletter promotionafter newsletter promotionNoem’s event on Wednesday was far bigger than two DeSantis events in western Iowa on Wednesday, one of which was right down the road. Asked by CBS News what she would do if offered the vice-presidential slot, the South Dakota governor said: “I think anybody in this country, if they were offered it, needs to consider it.”Rick Wilson, a cofounder of the Lincoln Project, an anti-Trump group, commented: “Noem is auditioning for vice-president, absolutely, which is why I think you’ll also see Elise Stefanik out there in the next couple of weeks also, because she is definitely trying to be vice-president. She’s not being shy about it at all; she’s telling people: ‘I want this gig.’”Wilson added: “Trump responds to people who are not just loyal. It’s subservience and a willingness to do whatever Trump wants you to do and so they’re checking a box. This is probably the minimum they can do to stay in his good graces. We’ll see more ‘respectable’ Republicans in the coming months also out there checking the box.”The former president’s absence from the campaign trail also reflects his dominance. Last month a Fox News poll put him at 52% among likely Republican caucus goers in Iowa, far ahead of DeSantis, at 18%, and Haley, at 16%. DeSantis has visited all 99 counties in the state but has made little headway.Trump is scheduled to host eight events in person before the caucuses, a small number compared with other candidates. He will skip a Republican primary debate hosted by CNN in Des Moines on Wednesday in favour of a town hall hosted by Fox News in the same city at the same time. He will hold his final rally in Cherokee on the eve of the caucuses and remain in the state on caucus night.His opponents have struggled to attract surrogates with star power. Haley’s backers include Will Hurd, a former congressman who dropped out of the race, and Chris Sununu, an ex-governor of New Hampshire, which holds the second nominating contest later this month. DeSantis has the support of Reynolds and Bob Vander Plaats, an influential Republican operative in Iowa and the chief executive of the Family Leader, a social conservative organisation.None is able to fire up the Republican base like Trump allies such as Greene, who was greeted by cheers in Keokuk, Iowa, on Thursday and proudly declared: “I’m a Maga extremist.”Sam Nunberg, a DeSantis supporter who was an adviser to Trump’s 2016 presidential campaign, acknowledged her influence: “Marjorie Taylor Greene, whatever the majority of Americans think of her, is very strong within the Republican primary so she’s a good surrogate to have, specifically for the people that [Trump] needs.“The strongest, most enthusiastic voters … would like the message of a Marjorie Taylor Greene and are on the same page as him, particularly about the 2020 election and issues with Biden. But in general a surrogate operation can only do so much. I’m not saying that he’s going to lose the caucus; I hope he does.” More