Easy, point out that he's an economic right-winger who takes lots of money from corrupt companies, and recites dumb one liners, and makes stupid comments like those in support of the border vigilanetes.
I doubt that's really sufficient to get someone elected. The people of California pretty much already knew they were electing someone who makes stupid comments. The two comments you said are pretty much standard Democratic complaints, so I doubt they will work all that great. People seem less bothered with Schwarzenegger's political leans than they do with the fact he is Schwarzenegger - which is exactly, weirdly, what got him elected.
Some people believed him when he ran as not being a politician in the recall election. That's not going to work in 2006. A lot of people are pissed at him doing stupid things like digging potholes to fill in for photo ops.
http://www.sfgate.com/cgi-bin/article.cgi?file=/c/a/2005/05/27/MNG9UCVOCH1.DTLUmmm, Kerry won by 10 points (which is worse than Gore and Clinton did), and Boxer won by 20 points, so it's not like the Democratic nominee needs any votes from people who never vote Democrat.
