Rep. Joe Heck (R) and former state Attorney General Catherine Cortez Masto (D) are tied at 37 percent among likely voters in a new Nevada Senate poll from Suffolk University.

The race for the seat being vacated by Senate Minority Leader Harry Reid (D-NV) has been closely watched and could decide the Senate majority. The TPM Senate Scoreboard shows the race as a toss up.

Third party candidates Tony Gumina, Tom Jones and Tom Sawyer all polled at 1 percent, and Jarrod Williams polled at 0 percent.

Suffolk University has not polled Nevada likely voters on the Senate election previously, but a CBS/YouGov poll showed Heck ahead by three percent, 38-35, earlier this month.

The poll was conducted Aug. 15-17 over the phone among 500 likely Nevada voters, and has a margin of error of plus or minus 4.4 percent.

TPM’s PollTracker Average of the Nevada Senate race shows Heck ahead of Masto, 37.3 to 36.3.