Rep. Mazie Hirono has an 18-point lead over former Rep. Ed Case in Hawaii’s Democratic Senate primary, according to an internal poll obtained by Roll Call.

Hirono took 54 percent compared with 36 percent for Case in the poll, which was conducted by Pete Brodnitz of Benenson Strategy Group for the Hirono campaign. By 45 percent to 25 percent, poll respondents said Hirono was the stronger general election candidate. Hirono, who was endorsed by the Democratic Senatorial Campaign Committee last week, received higher favorable and lower unfavorable ratings than Case.

“Hirono is in a strong position to become the Democratic nominee,” Brodnitz wrote in the polling memo. “She is more well-liked than Case, has a positive job approval rating (Case’s job approval is negative) … and has a substantial advantage on key attributes.”

Hirono and Case will face off in the Aug. 11 primary for the chance to take on former Gov. Linda Lingle (R) in the race for retiring Sen. Daniel Akaka’s (D) seat.

The poll of 800 likely primary voters was taken Nov. 15-19 and had a 3.46-point margin of error.