[20] Grisham was fired from a subsequent job at ad agency Mindspace over plagiarism charges, copying AAA material verbatim into her client's web page.

[18] She revoked the Arizona Capitol Times's press credentials hours after their reporting that the House speaker, David Gowan, had traveled at state taxpayers' expense during his campaign for Congress.

[25][6] In September 2015, Grisham worked as a press coordinator for Pope Francis's visit to Philadelphia as an independent contractor.

[26] Circa August 2015, Grisham started working as a press aide to Donald Trump's 2016 presidential campaign.

[10][27] After his victory, Grisham was named a special adviser for operations and won a place on Trump's transition team.

[9][27][28][29][30] Arizona House speaker David Gowan paid her $19,000 in state salary over an 8-week period while she was serving as a member of the Trump transition team.

[10][31] After Trump's January 2017 inauguration, Grisham was named deputy press secretary for Sean Spicer in the West Wing of the White House.

Despite losing Grisham as part of his own staff, President Trump said he was satisfied that the first lady would "be in good hands".

Grisham was described by several sources who had worked with her previously as being "highly competent" and "self-aware"; some suggested that she enjoyed "trolling the press".

In one instance, the piece linked to a Post story entitled "Trump becomes first sitting president to set foot into North Korea" as the authors asserted the paper had not reported the event.

[38] On September 23, 2019, when asked by the hosts of Fox & Friends if the White House planned to resume its daily press briefing, Grisham said "not right now...

"[42] On November 13, 2019, during the testimony of William B. Taylor Jr., Grisham commented that the impeachment inquiry against Donald Trump was a "sham hearing" that is "not only boring, it is a colossal waste of taxpayer time & money.

[46] On April 7, 2020, it was announced that Grisham left her role as White House Press Secretary and returned to the East Wing to be Melania Trump's chief of staff,[4] effective that same day.

[47] On the evening of January 6, 2021, Grisham resigned from her position as Melania Trump's Chief of Staff following the 2021 storming of the United States Capitol.

This included a text message exchange she related having with Melania Trump, who offered a curt, response when Grisham asked her if she wanted to address the public in order to call for an end to the violence.

According to Grisham, she asked Melania, "Do you want to tweet that peaceful protests are the right of every American, but there is no place for lawlessness & violence?"

"[48] In a December 2022 CNN interview Grisham told host Sara Sidner that Melania had come to believe her husband's lie that the election had been stolen.

[14][51][52] Anderson Cooper 360° devoted two prime-time segments in one week to question whether taxpayers should pay her $183,000 salary,[51] and to accuse her of hypocrisy.

[52] Authors Don Winslow and Stephen King pledged to donate $100,000 each to charity if Grisham held a one-hour briefing answering questions from the White House press corps.

[59] In 2024, Grisham stated that she didn't hold press briefings "because, unlike my boss, I never wanted to stand at that podium and lie.

[64] On August 20, 2024, Grisham spoke at the 2024 Democratic National Convention, saying that Trump mocked his supporters in private, calling them "basement dwellers", and that he had "no morals and no fidelity to the truth".

Politico reported that the relationship ended in 2020 after an argument in which Miller allegedly pushed Grisham up against a wall and slapped her in the face after she accused him of infidelity.

In August 2014, Grisham accepted a plea bargain agreement that reduced the charge to misdemeanor reckless driving, plus two years of probation.