In 2009 Frum denounced various anti-Obama conspiracy theories as "wild accusations and the paranoid delusions coming from the fever swamps".

In his blog, Frum described the Tea Party as "a movement of relatively older and relatively affluent Americans whose expectations have been disrupted by the worst economic crisis since the Great Depression.
They are looking for an explanation of the catastrophe—and a villain to blame.
They are finding it in the same place that (Michele) Bachmann and her co-religionists located it 30 years ago: a deeply hostile national government controlled by alien and suspect forces, with Barack Obama as their leader and symbol."
He explained Bachmann's political views, some of which he called "paranoid": "It emerges from a religious philosophy that rejects the federal government as an alien instrument of destruction, ripping apart a Christian society.
Bachmann's religiously grounded rejection of the American state finds a hearing with many more conventional conservatives radicalized by today's hard economic times."

On August 14, 2009, on Bill Moyers Journal, Frum challenged certain Republican political tactics in opposing health care and other Democratic initiatives as "outrageous," "dangerous," and ineffective.
As Congress prepared to pass the Patient Protection and Affordable Care Act in March 2010, Frum again criticized the Republican strategy of refusing to negotiate with President Obama and congressional Democrats on health care reform, saying that it had resulted in the Republicans' "most crushing legislative defeat since the 1960s".
Before making this statement, Frum had been associated with the American Enterprise Institute.
He resigned from the AEI a few days later.
Following the temporary withdrawal of a Republican effort to repeal the ACA in 2017, Frum wrote an article in the Atlantic in which he chastised fellow Republicans and conservatives for failing to take his advice to behave with moderation and humility.

In a September 2011 article, Tablet Magazine wrote: "as the Tea Party has come to dominate the GOP, Frum has been transformed in a remarkably short period of time from right-wing royalty to apostate" and quoted him as saying: "There's a style and a sensibility in the Republican Party right now that I find myself removed from, [but] you can do more good for the country by working for a better Republican Party than by leaving it to the extremists.
What have they done to deserve that inheritance?"

Writing for New York magazine in November 2011, Frum described his reaction to fellow Republicans, who had distanced themselves from him, saying, "Some of my Republican friends ask if I've gone crazy.
I say: Look in the mirror."
He described the development of an "alternative reality" within which the party, conservative think-tanks, and right wing commentators operate from a set of false facts about the economy and nonexistent threats to their traditional base of supporters.
He expressed concern over the inability of moderate Republicans to criticize their conservative brethren, contrasting this to the 1960s split between moderate Ripon Republicans and conservative Goldwater Republicans, when moderates such as Michigan governor George Romney were publicly critical of the conservatives.
In 2009 Frum denounced various anti-Obama conspiracy theories as "wild accusations and the paranoid delusions coming from the fever swamps".
In his blog, Frum described the Tea Party as "a movement of relatively older and relatively affluent Americans whose expectations have been disrupted by the worst economic crisis since the Great Depression. They are looking for an explanation of the catastrophe—and a villain to blame. They are finding it in the same place that (Michele) Bachmann and her co-religionists located it 30 years ago: a deeply hostile national government controlled by alien and suspect forces, with Barack Obama as their leader and symbol." He explained Bachmann's political views, some of which he called "paranoid": "It emerges from a religious philosophy that rejects the federal government as an alien instrument of destruction, ripping apart a Christian society. Bachmann's religiously grounded rejection of the American state finds a hearing with many more conventional conservatives radicalized by today's hard economic times."
On August 14, 2009, on Bill Moyers Journal, Frum challenged certain Republican political tactics in opposing health care and other Democratic initiatives as "outrageous," "dangerous," and ineffective. As Congress prepared to pass the Patient Protection and Affordable Care Act in March 2010, Frum again criticized the Republican strategy of refusing to negotiate with President Obama and congressional Democrats on health care reform, saying that it had resulted in the Republicans' "most crushing legislative defeat since the 1960s". Before making this statement, Frum had been associated with the American Enterprise Institute. He resigned from the AEI a few days later. Following the temporary withdrawal of a Republican effort to repeal the ACA in 2017, Frum wrote an article in the Atlantic in which he chastised fellow Republicans and conservatives for failing to take his advice to behave with moderation and humility.
In a September 2011 article, Tablet Magazine wrote: "as the Tea Party has come to dominate the GOP, Frum has been transformed in a remarkably short period of time from right-wing royalty to apostate" and quoted him as saying: "There's a style and a sensibility in the Republican Party right now that I find myself removed from, [but] you can do more good for the country by working for a better Republican Party than by leaving it to the extremists. What have they done to deserve that inheritance?"
Writing for New York magazine in November 2011, Frum described his reaction to fellow Republicans, who had distanced themselves from him, saying, "Some of my Republican friends ask if I've gone crazy. I say: Look in the mirror." He described the development of an "alternative reality" within which the party, conservative think-tanks, and right wing commentators operate from a set of false facts about the economy and nonexistent threats to their traditional base of supporters. He expressed concern over the inability of moderate Republicans to criticize their conservative brethren, contrasting this to the 1960s split between moderate Ripon Republicans and conservative Goldwater Republicans, when moderates such as Michigan governor George Romney were publicly critical of the conservatives.
David Frum