A poll conducted earlier this month shows a shift in the race for Arizona’s U.S. Senate seat. Democratic Congresswoman Ann Kirkpatrick now holds a slight lead over incumbent Republican Senator John McCain. Arizona Public Radio’s Ryan Heinsius reports.

The advocacy group MoveOn commissioned the study by the North Carolina-based Public Policy Polling. They interviewed nearly 750 Republican, Democrat and independent Arizona voters. Forty-three percent said they’d support Kirkpatrick if the general election was held today, while 41 percent would choose McCain.

In addition, 44 percent of the respondents said they’re less likely to vote for McCain after his endorsement of presumptive Republican presidential nominee Donald Trump.

McCain’s reelection campaign questioned the legitimacy of the study. But Public Policy Polling says the survey is nonpartisan. McCain and Kirkpatrick are considered the frontrunners in Arizona’s U.S. Senate race.