How badly do Republicans want to win the Senate seat from Delaware?  That’s the question that the latest Rasmussen poll poses as the candidates get ready for a primary to the special election to fill the rest of Joe Biden’s term in office.  Rep. Mike Castle, a moderate who has angered Tea Party activists nationwide with his support for cap-and-trade, nevertheless leads the Democratic nominee Chris Coons by eleven points, 48/37.  Tea Party favorite Christine O’Donnell, meanwhile, trails Coons in head-to-head polling by the same amount, 47/36:

Support for Republican Congressman Mike Castle falls just short of 50% for the third month in a row, but he continues to hold a double-digit lead over Democrat Chris Coons in Delaware’s U.S. Senate race.

The latest Rasmussen Reports statewide telephone survey of Likely Voters shows Castle earning 48% of the vote, while Coons gets 37% support. Six percent (6%) prefer some other candidate, and nine percent (9%) remain undecided. …

Coons leads conservative activist Christine O’Donnell, who is challenging Castle for the GOP Senate nomination in a primary next Tuesday, by a 47% to 36% margin. Given that matchup, eight percent (8%) prefer another candidate, while nine percent (9%) are undecided.

Last month, Coons held a similar 46% to 36% lead over O’Donnell after the candidates were virtually tied in July.

With eight weeks to go, a double-digit gap will be almost impossible to overcome, especially for a conservative Republican in a moderate state.  O’Donnell has stumbled over the summer against Coons while gaining some traction against Castle.  Some polls have suggested that the primary fight may be a dead heat.  With a week to go, both candidates will come out swinging in an effort to represent the GOP in the general election seven weeks later.

Will a primary win help O’Donnell solidify Republican support and beat Coons?  According to the internals of the Rasmussen poll, it’s not likely.  Castle actually gets more of the GOP vote against Coons (71/16) than does O’Donnell (63/20).  Castle also gets more of the Democratic vote (33%) than O’Donnell (16%), and independents as well (42/33, versus 37/43 for O’Donnell).

This really shouldn’t surprise anyone.  Delaware is not a red state; it’s usually a reliably blue state, especially in presidential elections.  They sent the explicitly liberal Biden to Washington for almost all of the VP’s adult life, and that was no accident.  In the era of Hope and Change, Delaware voters have begun to balk at the Democratic agenda, with a third of Democrats looking towards Castle rather than Coons, but that doesn’t make it a fertile ground for Tea Party candidates, either.  That doesn’t mean that Tea Party activists shouldn’t back O’Donnell if they feel Castle is too objectionable (and his cap-and-trade vote makes for a good argument along those lines), but don’t expect O’Donnell to pull off a big upset against Coons in November, either.

The question comes down to this: is it better to gain control of the Senate with Mike Castle in the caucus, or to miss that chance with Coons in the Senate instead?  And that may not have any easy answers, either.