Four candidates have pulled away from the field in the final weeks before voting begins, according to a Bloomberg Politics/Des Moines Register survey.

Less than three weeks before Iowa caucus-goers cast the first votes of the 2016 presidential election, the Republican contest in the crucial first heat has boiled down to two neck-and-neck races, one between U.S. Senator Ted Cruz of Texas and Donald Trump and another between U.S. Senator Marco Rubio of Florida and retired neurosurgeon Ben Carson.

A new Bloomberg Politics/Des Moines Register Iowa Poll shows Cruz and Trump, the two fiercest anti-establishment candidates, locked in a tight race for first place, well ahead of the rest of the pack. Following at a distance are Rubio and Carson, battling for third place.

Read the article “It’s Cruz vs. Trump and Rubio vs. Carson in Home-Stretch Iowa Poll” on bloomberg.com.