Poll: O'Donnell helped by Castle write-in

Support for Democrat Chris Coons drops below 50 percent if Castle enters race as write-in.

A new poll out Monday shows that if Rep. Mike Castle (R-Del.) were to wage a write-in bid in Delaware's Senate race this November, it could make the contest more winnable for Tea Party-backed Christine O'Donnell (R).

The Rasmussen poll found New Castle County Executive Chris Coons (D) still leading O'Donnell by nine percentage points in a hypothetical three-way race, but the Democrat's support came in under 50 percent.

The numbers have Coons ahead with 49 percent to O'Donnell's 40 percent. Castle gets just 5 percent of the vote as a write-in option, but most of that support appears to come away from the Democrat rather than O'Donnell. 

The numbers should be taken with a grain of salt given the difficulty in polling a write-in contest. Rasmussen said the automated survey asked respondents their choice in a two-way race between Coons and O'Donnell with no mention of Castle. Only when the response options were listed were respondents given the choice of voting for Castle.  

The survey polled 500 likely voters and has a margin of error of plus-or-minus 4.5 percentage points. 

Castle said last week that he is considering waging a write-in bid this November after losing to O'Donnell in the Republican primary. The congressman has until September 30 to make a decision. September 30 is the state's deadline for declaring a write-in campaign.