After spending $1 million in Iowa to tear down Donald Trump, the Club for Growth is out with a new poll of 500 likely caucus goers showing the Republican front-runner has blown his lead.

The survey, conducted over the weekend by the club’s longtime pollster, Basswood Research, showed the New York billionaire businessman and reality television star trailing Ben Carson by five points. The retired pediatric neurosurgeon led the pack at 21 percent, followed by Trump at 16 percent, Sen. Marco Rubio of Florida at 11 percent and former Florida Gov. Jeb Bush and ex-Hewlett Packard CEO Carly Fiorina, both at 10 percent. The survey’s margin of error was plus or minus 4.4 percentage points.