Charles Djou’s stay on Capitol Hill was supposed to be brief.
The 40-year-old lawyer’s surprise win in Hawaii’s special House election in May was widely seen as a fluke: a Republican in a heavily liberal district who won with 39 percent of the vote after feuding Democrats refused to settle on a single candidate and split their vote.
Experts confidently predicted that in November, the seat in the Honolulu-based 1st Congressional District — the childhood home of President Obama — would flip back to the blue column, offering Democrats a chance for a rare pickup in a bleak midterm landscape.
But five months later, the rookie Republican congressman is hanging tough, locked in a virtual dead heat with the Democratic state lawmaker Colleen Hanabusa, one of the Democrats he defeated last spring.
In a Public Policy Poll commissioned by the liberal website Daily Kos released this week, Mr. Djou drew 47 percent versus 48 percent for Mrs. Hanabusa, whose website currently features prominently the endorsement she received last week from Mr. Obama. The poll showed 5 percent undecided and a margin of error of nearly 4 percentage points.
“It’s definitely problematic 28 days out for the Democrats in a state where they’re supposed to have a pretty strong hold,” Dylan Nonaka of the Hawaii Republican Party told Honolulu television station KHON on Tuesday.
The Rothenberg Political Report in an analysis of the race late last month warned Democrats against overconfidence.
“There is little evidence that voters are willing to throw Djou out of office after only a couple months on the job,” the nonpartisan political publication noted. “… This race is not over, and Djou may even have the advantage.”
And Mr. Djou isn’t the only Republican surprise in a state that the president won with more than 70 percent of the vote in 2008.
In the governor’s race, the same Daily Kos poll found that GOP candidate Duke Aiona, the state’s lieutenant governor, has erased what was once a double-digit gap with Neil Abercrombie — the Democrat who earlier this year resigned the House seat Mr. Djou now holds to run for governor.
Mr. Aiona is hoping to take over for the current GOP governor, the term-limited Linda Lingle.
The races on paper were not supposed to be competitive. Democrats have held the House seat for all but four years since it was first carved out in 1971, including 11 terms for Mr. Abercrombie before he quit. Before Mrs. Lingle was elected in 2002, Democrats had held the governorship for 40 years.
The candidates said the latest poll numbers would have no impact on their campaigns.
“Forget about these polls,” Mr. Aiona told KHON. “It doesn’t matter. What matters is the ideas that we have. I don’t care if it’s 20 points the other way, you should be excited.”
Mr. Abercrombie said, “We’ve learned a long time ago that the only poll that matters is on Election Day.”