U.S. Sen. Daniel Inouye holds a 13-point lead over Republican challenger Cam Cavasso in his bid for a ninth consecutive term, according to a Rasmussen Reports poll.

The poll, released Sunday, shows Inouye with 53 percent of the vote, followed by Cavasso with 40 percent and 4 percent undecided.

Cavasso, a former state representative, also ran against Inouye in 2004 and lost by a 75-21 margin.

This is the first Rasmussen survey of the race to include Cavasso, who won the Republican primary on Sept. 18 with 67 percent of the vote. In June a Rasmussen poll showed Inouye with a better than 3-to-1 lead over his only Republican opponent at the time, John Roco.

The telephone survey of 500 likely voters was conducted Wednesday by Pulse Opinion Research for Rasmussen. The margin of error is 4.5 percentage points.

Cavasso, 60, said the poll shows his support is growing quickly.

"In this particular case it’s a reason for rejoicing," he said.

Cavasso said polls showed he was 39 points down three months ago and 23 points down 12 days ago. He said he thinks the reason for his rise in the polls is a difference in values with Inouye.

"I absolutely believe that the values he stands for are unacceptable to the majority in Hawaii," Cavasso said.

Inouye, 86, first elected in 1962, is Senate president pro tempore, third in line to the presidency.

"We’re working hard on all islands. This election is very important to the Senator and every vote counts. Our internal polls are significantly different than what Rasmussen reported," said Inouye spokesman Peter Boylan.