U.S. Rep. Ed Case yesterday released the results of a poll that showed him about even with U.S. Sen. Daniel Akaka in their campaign in the Democratic primary for U.S. Senate.

The poll, paid for by the Case campaign and taken by QMark Research & Polling in late April and early May, asked 700 likely voters who they would support if the election were held today. Akaka received the support of 40 percent, Case was at 38 percent and 22 percent were undecided. The survey had a margin of error of 3.7 percent.

QMark also asked questions about Case's campaign themes of transition, experience, performance and change and then asked voters a second time who they would support. Case came out at 44 percent, Akaka at 39 percent and 17 percent were undecided.

Case, in an e-mail to his supporters, said he conducted the poll to confirm the viability of his candidacy and to demonstrate broad-based support. He also said the results show the potential benefits of a series of statewide debates to help voters distinguish between the two candidates.

"It also demonstrates that, as Hawai'i's voters think through the big picture of Hawai'i's representation in our U.S. Senate now and over the next generation, they increasingly favor my candidacy," Case wrote.

Elisa Yadao, a spokeswoman for Akaka's campaign, said Akaka's team also had done polling recently but preferred not to release the results. "We are going to be running, as we said all along, an energetic and vigorous campaign that's going to make sure that the voters are clear on Senator Akaka's voting record, and his accomplishments, and his commitment to the people and the voters of Hawai'i," she said.

Reach Derrick DePledge at ddepledge@honoluluadvertiser.com.