By January 2019, his show dropped to third with 2.8 million nightly viewers, down six percent from the previous year. The show had lost at least 26 advertisers. There were calls to fire Carlson from Fox News in March 2019 after Media Matters resurfaced remarks on women he had made over several years to the radio show Bubba the Love Sponge, but his ratings rose 8 percent that week despite the boycotts. By August 2019, Media Matters calculated that some companies had fulfilled their media buy contracts and advertising inventory for the time slot and had now begun their purchases for other time slots on Fox News. At the close of 2019, Carlson's Nielsen ratings among all viewers 25–54 placed him second only to Fox's The Sean Hannity Show among cable news shows.
In 2019, in his monologue on Tucker Carlson Tonight, Carlson said America's "ruling class" are, in effect, the "mercenaries" behind the decline of the American middle class:
In January 2019, Carlson used a Washington Post op-ed by Mitt Romney to criticize what he described as the "mainstream Republican" worldview, consisting of "unwavering support for a finance-based economy and an internationalist foreign policy," which he argued was also supported by the bulk of Democrats. He cited parallels, in regard to economic and social problems which had befallen inner cities and rural areas, despite cultural and demographic differences between their respective populations, as evidence that the "culture of poverty," which had been cited by conservatives as the cause of urban decline, "wasn't the whole story:"
In May 2019, Carlson defended Trump's decision to place tariffs on Mexico unless Mexico stopped illegal immigration to the United States. Carlson said, "When the United States is attacked by a hostile foreign power it must strike back, and make no mistake Mexico is a hostile foreign power."
In May 2019, after Robert Mueller gave a statement saying the Special Counsel investigation on Russian interference in the 2016 election did not exonerate President Donald Trump of obstruction of justice, Carlson called Mueller "sleazy and dishonest."
When President Trump met the North Korean leader Kim Jong-un at the country's border with the South in June 2019, Carlson told Fox & Friends said "there's no defending the North Korean regime, it’s the last real Stalinist regime in the world. It’s a disgusting place obviously", but "you've got to be honest about what it means to lead a country, it means killing people." Carlson went on to argue that although "not on the scale that the North Koreans do, but a lot of countries commit atrocities, including a number that [the United States] are closely allied with."
Of illegal immigration, Carlson said in May 2019, "The flood of illegal workers into the United States has damaged our communities, ruined our schools, burdened our healthcare system and fractured our national unity." In December 2019, he falsely claimed that immigrants were responsible for making the Potomac River "dirtier and dirtier."
In call-in segments Carlson made from 2006 to 2008 on the radio show Bubba the Love Sponge, Carlson said Iraq was not worth invading because it was a country made up of "semi-literate primitive monkeys" who "don't use toilet paper or forks." He also criticized "lunatic Muslims who are behaving like animals," and said that any presidential candidate who vowed to "kill as many of them as [they] can" would be "elected king." Recordings of these segments were released online in March 2019 by the progressive Media Matters for America. The Washington Post labeled these comments racist.
Carlson concluded Tucker Carlson Tonight on July 9, 2019, with a 3-minute monologue about Rep. Ilhan Omar (D-MN), calling her ungrateful to the United States, where she had been granted asylum, and calling her "living proof that the way we practice immigration has become dangerous to this country." His monologue was described by The Guardian as "racially loaded" and "full of anti-immigrant rhetoric." Congresswoman Omar responded on Twitter, saying that "advertisers should not be underwriting this kind of dangerous, hateful rhetoric." In its July 10 article on the incident, The Daily Beast commented that, mainly because of "right-wing attacks that have then been amplified by members of Congress and the president," Omar has been receiving death threats since she was elected to Congress. According to the article, while Carlson "has devoted numerous segments" of his show to criticizing her, this time Carlson "took his anti-Omar stance even further."