WASHINGTON — In the past few months, President Donald Trump has invited supporters wearing “Make America Great Again” campaign gear on stage with him during official presidential speeches. He has criticized Democratic rival Joe Biden in Rose Garden addresses. He has played campaign-style videos in the White House briefing room and he has used his campaign playlist, typically reserved for rallies, at official presidential events.

Presidents running for re-election have traditionally worked to balance official government business with campaign activity. But government watchdogs and officials from past administrations warn that Trump has smashed that norm, displaying an unusual willingness to use his presidential platform for political purposes.

Trump’s penchant for blurring the lines between his campaign and his official duties came to a head last week when he confirmed he was considering giving his acceptance speech for the Republican presidential nomination — one of the most anticipated moments of the election season — from the White House South Lawn.

“I’ll probably do mine live from the White House,” Trump said on Fox of the upcoming address. “…The easiest, least expensive and, I think, very beautiful [location] would be live from the White House.”

Presidential ethics veterans said the savings weren’t his to take. “What Trump is doing is a form of stealing,” said Norman Eisen, who served as special counsel and special assistant to the president for ethics and government reform in President Barack Obama’s administration.

“The taxpayer entrusts funds to the government to do the official business of the government. If they want to support a political candidate, they make a political contribution. For Trump to effectively be reaching into all of our pockets to subsidize his proposed activity on the South Lawn… No, the taxpayer should not have to pay for that.”

Trump’s boundary-stretching moves go beyond the location of his acceptance speech, Eisen and others say.

The president has increasingly turned official White House events, both in Washington and on the road, into political events as the coronavirus pandemic has kept him off the usual campaign trail and unable to hold large in-person rallies.

Since March, Trump has taken official presidential trips to Pennsylvania, Michigan, Wisconsin, Georgia, North Carolina and Ohio. He has also made multiple visits to Arizona, Texas and Florida. All of these states are critical to Trump’s re-election.

“It’s always been a fine line that presidents ride with making sure that the official activity in an election year does not go too far into campaign activity,” said Kedric Payne, general counsel and senior director of ethics at the Campaign Legal Center. With Trump, Payne said, he is “barely disguising it as official activity.”

On an official government trip to Texas in July, for example, a senior administration official told NBC News that the visit was to highlight Trump’s energy policy and contrast it with that of Biden’s. On another official White House trip to Arizona in June, the president headlined an event hosted by Students for Trump at a Phoenix church.

On his most recent presidential trip last week, to Ohio, the White House said Trump was met on Air Force One by a campaign senior adviser in the state, Bob Paduchik. The president held a small campaign-style rally on the tarmac, then visited a Whirlpool factory where he used his remarks to make fun of his presumptive fall opponent (“Did you ever watch Biden, where he’s always saying the wrong state?”) He rounded out the journey with a supporter roundtable and a campaign fundraiser.

These trips can become expensive when the airfare and the cost of federally mandated Secret Service protection are taken into consideration.

When a presidential trip involves both official and political events, the White House is supposed to use a formula to determine the amount of money that should be reimbursed by the campaign or the party to the Treasury Department, so as to protect taxpayers from paying for any political activities. That formula is not generally made public.

A spokesperson for the Federal Election Commission said that to distinguish political travel from official travel, the purpose and the nature of the events at each stop should be taken into consideration by the White House.

According to FEC data, the Trump campaign and the Republican National Committee have reimbursed more than $600,000 to the Treasury since May for airfare. Neither the Trump campaign nor the RNC provided NBC with a breakdown of for which trips taxpayers were reimbursed.

Trump has also officially hosted a number of constituent-based events at the White House since the pandemic hit, involving truck drivers, farmers, veterans and seniors — a key voting bloc whose support for the president has slipped amid the pandemic. Five of the nearly two dozen events have been with faith leaders, a demographic that propelled Trump to victory in 2016 but whose support this time around has softened.

The Trump campaign has pushed back against criticism that the president is misusing White House events.

“Democrats and the media are desperate to muzzle President Trump. They don’t want him tweeting, they don’t want him holding rallies, they don’t want him speaking at Mount Rushmore, and now they don’t want him holding press conferences,” said Tim Murtaugh, Trump 2020 communications director. “Every week, Joe Biden reads speeches off the teleprompter attacking the President and the media gleefully reports every word, and President Trump is entitled to fight back.”

While there are some clear rules governing what sort of political activity the president can engage in on official trips and on White House grounds (he cannot make fundraising calls from the Oval Office, for example), much of the president’s political actions are guided by tradition and norms.

The Hatch Act, a law limiting the political activities that federal employees can engage in to ensure that federal policies are carried out in a nonpartisan fashion and to protect federal workers from political coercion, does not apply to the president.

Officials from past administrations say that decoupling the political from the policy can be difficult, and many relied on White House lawyers, advisers and watchdogs to avoid Hatch Act and ethics violations.

“They were afraid of losing Congress so they pushed the envelope on a bunch of things,” said Richard Painter, a Trump critic who served as chief White House ethics lawyer in the George W. Bush administration, recalling the 2006 midterm elections when he frequently had to push back on some actions by administration officials.

Still, said Greg Jenkins, deputy assistant to the president and director of White House advance for Bush, “we had a policy that drew a bright line between official and political events.”

“All White Houses do events at the White House that advocate or oppose particular policies or proposals. While those are done for political purposes — to persuade people to your side — they weren’t electioneering,” Jenkins said.

Johanna Maska, White House director of press advance to Obama from 2009 to 2015, said that she and other officials would receive regular Hatch Act and ethics training from the White House counsel.

Maska said she recalled discussions during the 2012 campaign about whether using Obama’s official armored podium with the presidential seal at political events was an example of undue influence and a burden on taxpayers. Ultimately the campaign decided to buy their own armored podium for Obama to use at events, which, Maska recalled, was expensive.

“Our typical default was we wanted to pay for everything to make sure we were following the law and weren’t making any in-kind contributions,” Maska said.

Eisen, the special counsel to Obama, said establishing a strict set of rules on the use of Air Force One and reimbursements, among other ethics issues, was a “huge priority” for the administration. “I personally trained everyone in the White House on these rules so they wouldn’t break them.”

Eisen recalled telling Pete Rouse, a senior adviser to Obama and an avid Grateful Dead fan, that he had to take down an Obama poster hanging in his office signed by the band because “there can be no taint of politics in this workplace, which is for policy.”

Government watchdogs say that Trump has strayed far from the ethics norms of past administrations. They say it sets a dangerous precedent could erode public trust.

“There are all sorts of debates and the thing I was proud about is that our counsel would challenge us to make sure we were making the best decision for the taxpayers,” said Maska. “My question is: what is this counsel doing?”