Which door will Rep. Mike Castle choose?

I think Representative Mike Castle should go after the Senate seat opening up in 2010 from Delaware. He already has the experience in the House with his 16 years of service and he could move onto a bigger stage in the Senate. I think he would definitely put up a good fight against Vice President Joe Biden's son given his more moderate stance on some of the big issues. The one area that the younger Biden could take advantage of if Castle doesn't run is the need to spend on transportation and infrastructure like Amtrak. Given that it is one of the more heavily invested states in the system, the large sum of money that VP Biden was able to accrue for the company was significant and his son's war service will only serve to boost the state's interest in him. I found it hard to believe that Beau was actually trailing in a poll with Castle as late as March because I thought he would have been a shoe-in to replace his father for Delaware. If Republicans can win this seat with Castle then maybe it will not be so bad for them come the midterm election cycle.