You can use this link to easily alert your senator of your objection.
http://mailcenter2.comcast.net/wmc/v/wm/43285917000CD063000037E32205886360040A9B020E030B?cmd=Show&no=1239&uid=58797&sid=c0
excerpt:
If Roberts, who is only 50 years old, is confirmed as Chief Justice, he could lead the Court for the next 30 years or more and have a profound impact on the lives of ordinary Americans. Roberts is nominated to become the most powerful judge in the country, but President Bush still refuses to release documents from Roberts' time as a top political appointee in the first Bush administration.