He's a stooge for the Republican Party, willing to bend or break the law to support his party, regardless of the effect it has on the people.
Case in point -- the Jack Abramoff scandal. In 2002, McCain led the committee that investigated the scandal and while he completely let crooks like Tom DeLay off the hook, one part of the investigation in particular, seems to border on criminality on McCain's part.
In an e-mail recently reported about on The Huffington Post, it's clear that McCain knew about the time about the involvement of Alabama gubernatorial candidate Bob Riley in the Abramoff scandal. But this connection didn't appear in McCain's report and wasn't released until long after Riley defeated incumbent Don Siegelman in a contested and shady election by a mere 3,000 votes. Once of the concerns for Siegelman was potential ethical concerns quite similar to those Riley is accused of. If it wasn't "faulty" voting machines that threw the election to Riley, certainly the withholding of valid and relevant evidence by McCain did.