It looks like there’s a real possibility of a major upset in the Delaware Senate primary on Tuesday night, with insurgent conservative Christine O’Donnell leading longtime Congressman and Governor Mike Castle 47-44. That 3 point lead is well within the poll’s margin of error.
If Castle is indeed defeated Tuesday night it will be yet another sign that conservatives have a strangle hold on the Republican Party and moderates may or may not be welcome anymore. Castle has an overwhelming 69-21 lead with moderate voters but they only make up 33% of the likely primary electorate. O’Donnell has a 62-31 lead with conservatives that’s more than enough to propel her to the overall lead.
It’s clear that Castle’s popularity has taken a sharp turn in the wrong direction over the last month. An August PPP poll found his favorability with Delaware Republicans at a 60/25 spread. Now his favorables within the party are negative at 43/47. That’s largely a product of 55% of voters in his party saying they think he’s too liberal compared to 37% who think he’s about right.
GOP voters are pretty sharply divided about O’Donnell as well. 45% have a favorable opinion of her with 41% seeing her unfavorably. Only 50% of primary voters think she’s fit to hold public office but she does much better than Castle on the ideology front- 53% think she’s about right.
If O’Donnell pulls it out Tuesday night it will be a major victory for Delaware’s small but united group of Tea Party voters. Just 25% of Republicans in the state consider themselves to be members of that movement but they give her a 79-18 advantage that’s more than enough to overcome her 52-39 deficit with everyone else.
Assessing the impact of Sarah Palin's endorsement is similar to the Tea Party numbers. Only 35% of Republicans in the state say they're more likely to vote for someone with Palin's support to 24% who say it's a negative and 41% with no opinion. But O'Donnell is really running up the score with that third for whom it is a positive, leading Castle 83-13. That outweighs Castle's 82-11 lead with people who say it's a negative and his 49-41 advantage with people who don't care.
This race is too close to call and could certainly go either way Tuesday night. General election Senate numbers we'll release later this week make it clear the biggest beneficiary of this primary becoming so unexpectedly hotly contested is Chris Coons. He would start out with a large advantage over O'Donnell in a general election match up, and is polling closer to Castle than he was when PPP polled Delaware last month.
Full results here