Businessman and real-estate mogul Donald Trump has a 10-point lead over rival Sen. Ted Cruz (R-TX) in Iowa, according to an Emerson College Polling Society poll released Thursday.

The poll showed support for Trump at 33 percent, with his closest runner-up, Cruz, at 23 percent. Cruz enjoyed an nine-point advantage over Sen. Marco Rubio (R-FL), who took third place with 14 percent.

The survey, which comes amid a fierce contest between Trump and Cruz in the final days leading up to the Iowa caucuses, was concluded the day after former Alaska Gov. Sarah Palin (R) endorsed Trump at an Iowa rally. This is Emerson’s first poll of the GOP contest in Iowa, so it’s difficult to tell whether that endorsement contributed to Trump’s lead over Cruz.

The Emerson College Polling Society telephone poll was conducted by phone from Jan. 18-20 and surveyed 271 likely Republican voters, with a margin of error of 5.9 percentage points.