For practicality's sake, the situation is not the same for a House member. If Hunter resigned at this point, there would have to be a special election scheduled held, but since House members are elected every two years, the "special" election would be put off until the general election in November. If a Senator's term were to expire at the end of the year as is Hunter's, I would allow them the same consideration. However, in Liebermann's case, his term did end, yet he ran for re-election to the Senate at the same time he was running for VP. To me, this is just plain wrong.
In Hunter's case (as with any House member), I will concede that he probably knew he was going to run for President as he ran for re-election in 2006, so he should have resigned his seat then. This also would apply to Sen. Clinton who should have refrained from seeking re-election to the Senate in 2006 since she knew she would be running for the Whitehouse in 2008.