Thompson was involved in campaign finance reform, which is good, but he's still a hard line conservative.
In case anyone is wondering where he stand on certian issues:
http://www.ontheissues.org/senate/Fred_Thompson.htm
He's a homophobe, for one, voting against having sexual orientation included in hate crimes and against gay marriage. He voted in favor of the bullshit law ruining bankruptcy. He voted for limiting death penalty appeals, which suggests that he is pro-death penalty. He wants to drill ANWR. He voted to de-fund solar and renewable energy. He's probably against gun control. He's pro-big medicine.
However:
He may be pro-environment, as he voted to restrict the funding for building roads in National Forests. He's pro-immigration (which surprises me). He doesn't want to privatize social security, which is great.
My main beef is that he voted to authorize the war, despite the fact he reformed on Kosovo during the Clinton administration.