Former Hawaii Gov. Linda Lingle (R) is within striking distance of both of her Democratic opponents, according to a poll released Wednesday afternoon by the Democratic-affiliated Public Policy Polling.

Lingle trails Rep. Mazie Hirono by 48 percent to 42 percent and leads former Rep. Ed Case by 45 percent to 43 perecnt.

According to the poll, Lingle's approval numbers have improved since she left office: A narrow majority of Hawaii voters have positive views of her, up from a 10 point disapproval gap seven months ago.

The three are running to replace retiring Sen. Daniel Akaka (D-Hawaii), a must-win seat for Democrats if they hope to retain control of the Senate. Republicans need just four seats to retake control of the Senate (if President Obama wins reelection), and Democrats are defending many more seats than the GOP this election.

Hirono leads Case among Democratic primary voters by 45 percent to 40 percent, with that lead coming from a 4-to-1 advantage among self-identified "very liberal" voters. Case, a centrist who was part of the fiscally moderate Blue Dog Coalition while in Congress, is disliked by many liberals in the state and infuriated many in the Democratic establishment when he ran against Akaka in a 2006 primary.

Hirono does better than Case in the general-election match-up even though he is better liked by Republicans and Independents because she does better with the liberal base, according to the poll.

The poll of 568 voters, including 368 Democrats, was conducted from Oct. 13-16, with a margin of error of plus or minus 4.1 percent and 5.1 percent in the Democratic primary portion.