Bowman also notes Nicholson's performance:

With Payne's snaffle between his teeth and blinders firmly fastened down, Nicholson turns in what may be the finest performance of his career as Warren Schmidt, a retired insurance man from Omaha.

In contrast, David Edelstein wrestles with what the movie is trying to say while still acknowledging Nicholson's performance.

Payne and his co-writer, Jim Taylor, have largely discarded the Louis Begley novel (set in an affluent, New York milieu) with which they began. As in Citizen Ruth (1996) and Election (1999), they're out to chart the distinct dementia of the "red" states in the vast middle of the country. And although Payne has chosen until recently to make his home in Nebraska, he seems to regard the so-called heartland as a barren place, indeed—a place where souls go unwatered. Schmidt's retirement party is marked by numbingly generic toasts; and even when his drunken best friend, Ray (Len Cariou), lurches to his feet to dismiss the previous encomiums as b.s., Ray ends up spouting a different (and no more insightful) set of chestnuts. One scene, in which the bored Schmidt goes to visit his "young-punk" successor, has been constructed entirely of clichés: from "Hey, there he is!" to "You look great—you been workin' out?" This is the code of Midwestern American capitalism, as rigid in its ways as a Japanese tea ceremony—only enacted by people who don't realize that their modes of discourse have been so deadeningly channeled. Payne's Midwest is a land that has apparently not discovered irony.

For Edelstein Nicholson's performance is not matched the by the movies meaning. The movie fails to move him:

Payne's movie is flat, depressed, and at times—given this director's talent—disappointingly curdled; it needs every quivering molecule of Nicholson's repressed rage to keep it alive and humming.

The New York Times' Stephen Holden, on the other hand, loved the entire package:

Of all the dramatic transformations Jack Nicholson has undergone in his 44-year screen career, none is more astonishing than his embodiment of a retired, widowed insurance executive from Omaha in Alexander Payne's film "About Schmidt." Plodding in a weary, stiff-legged shuffle, his shoulders bowed, his features half-frozen into the guarded, sunken expression of someone who has devoted decades of thought to actuarial calculation, his character, Warren Schmidt, is a staid Middle American everyman who finds himself adrift at the precarious age of 66. Warren may be the least colorful character Mr. Nicholson has ever played on the screen, and the role inspires this great actor's least flamboyant performance. The Mephistophelean eyebrows remain at half-staff, and the ferocious bad-boy grin that has illuminated many of his most famous roles with jagged lightning is stifled. Instead of flash, what Mr. Nicholson brings to his role is a sorrowful awareness of human complexity whose emotional depth matches anything he has done in the movies before . . . In "About Schmidt," as in "Election" and "Citizen Ruth" (the first film this director created with his screenwriting partner, Jim Taylor), the team brilliantly reconciles a double vision of American life. While one eye gazes satirically at the rigid institutions and shopworn rituals that sustain a sense of order and tradition in the heartland, the other views those same institutions with a respectful understanding of their value . . . What makes this exquisitely observed slice of American screen realism transcend itself is finally its moral sensibility. The movie's quest to discover how one ordinary person can make more of a difference turns out to be as serious as its title character's. The common-sense answer it comes up with, in a final scene so unassuming that it's almost a throwaway moment, is as simple and modest as it is profoundly moving.