Democrat Rob Sand has opened a double-digit lead over Republican Zach Lahn in Iowa’s governor race, according to a new Suffolk University poll.

The survey, conducted October 1-4 among 500 likely voters with a margin of error of 4.4 points, puts Sand at 55 per cent and Lahn at 43 per cent. The RealClearPolitics average shows Sand ahead by about seven points.

The result is striking for Iowa, which has not elected a Democratic governor in two decades. Republicans hold a registration advantage of more than 180,000 voters in the state.

No public poll has shown Lahn leading the race. The Cook Political Report and the Sabato Crystal Ball both rate the contest as leaning Democratic.

The candidates met in their first debate on October 6. Early voting begins October 14, with the election on November 3. Analysts say the race is now the Democrats’ best pickup opportunity in the country.