Hyperbole, I hope. “Let the free market decide” was the conservative Republican position pre-911. Closed borders was the union Dem position. Pre-911 Hannity and other conservatives ridiculed Pat Buchanan as the only conservative to be against the free market.
So the current effort is to just go back to pre-911 conservativism...but the Reagan-Kemp optimism; not the Buchanan Malthusianism.
The pre 911 argument was to close the borders. That was the position since the early 1950s when Eisenhower hauled the Mexicans to the border and kicked them out.
Trying to figure out when a real Conservative was in favor of open borders and it does not come to mind. You go all the way back to 1604 and you find King Philippe of Spain handing over much of North America to others with directions regarding BORDERS. He paid to continue a survey earlier commissioned by his father.
Philippe was certainly a Conservative in anyone's estimation!