Turns out Lindsay Lohan was perfectly cast in "Liz & Dick."Not because she's good as Elizabeth Taylor in this TV movie (Sunday, 7 and 9 p.m., Lifetime). Because she's absolutely terrible in a movie that's a laughable mess.It's difficult to express just how awful "Liz & Dick" is. It's actually a series of otherwise almost unrelated scenes strung together, connected by Taylor and Richard Burton (played by Grant Bowler) sitting in heaven talking about their lives.I am not making this up.There's all sorts of scenery chewing as the couple fight and make up, fight and make up, fight and make up.If I didn't know better, I'd think this was an intentional comedy. And there is some entertainment value in laughing at how utterly awful it is.But, ultimately, it's the latest chapter in Lohan's decline from talented child star to tabloid target and irrelevancy.