[18] During his college years, Masters contended that Iraq and al-Qaeda were not "substantial threats to Americans", calling for "unrestricted immigration" and an isolationist foreign policy.

He added: "I suppose it was only a matter of time before I got called antisemitic for criticizing wartime propaganda in an essay I wrote as a teenager.

[18][19] The Anti-Defamation League criticized him, and Masters' primary rival Jim Lamon ran television ads highlighting the posts.

[33] In March 2022, Masters resigned from his positions at Thiel's investment firm and foundation to campaign in the 2022 Arizona Senate race.

[29][34] In April 2021, Masters reappeared as a potential candidate for the Republican nomination for U.S. Senate in 2022, challenging incumbent Democrat Mark Kelly.

[29][35] Masters officially entered the race in July 2021,[36][37] and Thiel gave an additional $3.5 million to the pro-Masters super PAC in May 2022.

[40] During a Republican primary debate, Masters said that he supported impeaching President Joe Biden and removing him from office due to border enforcement issues.

[44] During his campaign, Masters cited the book Beautiful Losers, a collection of white supremacist writer Sam Francis' essays, as an influence on his style of conservatism.

[51] During his 2022 Senate campaign, Masters invoked the Great Replacement conspiracy theory, saying that Democrats "hope to just change the demographics of our country...

[51] Masters said that if elected to the Senate, he would vote to confirm federal judicial nominees only if they "understand that Roe and Griswold and Casey were wrongly decided".

[56] In August 2022, following the Dobbs v. Jackson Women's Health Organization U.S. Supreme Court case that overruled Roe v. Wade, Masters "scrubbed" his campaign website and "softened his rhetoric" by "rewriting or erasing five of his six positions" on abortion including the removal of his "100% pro-life" text.

[57] His position, as of August 2022, is that he favors "a federal personhood law that would ban abortions nationwide after the beginning of the third trimester", unless the life of the mother is at risk.

[61] In a statement to the New York Times, Master denied that he promotes the Great Replacement theory, saying that "It is obvious to everyone that Democrats see illegal immigrants as future voters.

[53] While clarifying that he did not endorse Kaczynski’s bombings, Masters said that Industrial Society and Its Future, the domestic terrorist’s manifesto, contained "a lot of [correct] insight".

[66][67] An Arizona-based GOP strategist told The Hill that the "Ted Kaczynski gaffe" was partly responsible for Master's falling poll numbers.

[67] In August 2021, Masters called for new leadership in the U.S. Armed Forces due to perceived partisan leanings, saying "I would love to see all the generals get fired.

[69] Meeting with conservative Tea Party activists in March 2022, Masters questioned whether the FBI was involved in the January 6 United States Capitol attack.

[51][71] He supported Elon Musk's proposed acquisition of Twitter, called for legislation to treat major social media companies as "common carriers" and to regulate Google's search algorithm.

Certainly they should at least be married", so that they can "relate to a constituency of families, or govern wisely with respect to future generations"; Masters said this three months after criticising his Republican primary rival Abe Hamadeh as a politician "we don't need" for having "no wife and kids, no skin in the game".

[72] Donald Trump initially did not endorse Masters in the primary, instead supporting Hamadeh, an unsuccessful candidate for Arizona attorney general in 2022.

[73] Masters caused controversy during the 2024 campaign for referring to Hamadeh, who identifies his faith as both Druze and Muslim, as a "terrorist sympathizer.