I sent the following email to Senator Grassley today. I think that it's pretty self-explanatory. The grudging respect that I used to have for him has declined, but I keep hoping that he'll go out with a renewed sense of independence and courage.
Dear Senator Grassley,
I urge you to support the proposed assault weapons ban. I was disheartened by this article (http://www.nytimes.com/2013/03/20/us/politics/senate-gun-bill-will-exclude-assault-weapons-ban.html?hp&_r=0), but with your support--and you really have no electoral consequences to fear, do you?--you could make a difference. You can make Iowans proud and (most importantly) safer. Everyone knows the feared power of the NRA, but please don't let it control you. I shouldn't think that caving into the threats of the NRA is the legacy that you want to leave.
Thank you for your consideration.