"Trump is a philosophically unmoored political opportunist who would trash the broad conservative ideological consensus within the GOP (Republican Party) in favor of a free-floating populism with strong-man overtones," National Review said.
The magazine's argument is one that has been made by several of his rivals for the 2016 Republican presidential nomination, most notably by former Florida Governor Jeb Bush.
But nothing has stopped Trump from seizing control of the race and putting him in position to win not only Iowa's caucuses but also New Hampshire's first-in-the-nation primary on Feb. 9.
A CNN/ORC poll on Thursday said Trump had taken a solid lead over Texas Senator Ted Cruz in Iowa, with 37 percent to 26 percent for Cruz. Cruz has led other polls in Iowa.
National Review said Trump, a New York billionaire and former reality TV star, had in the past supported abortion, gun control, and higher taxes on the wealthy, all positions that conservatives oppose.