Never brought to trial, he was brought before an "impeachment" which is an entirely political process. Plus, he was not brought up for impeachment for the supposed sexual acts, he was brought up for lying about them.
How could he be brought up for lying about them, if there was no process (political or otherwise) regarding the supposed sexual acts in the first place?
Lewd? Perfectly normal. And legal. We have a good married friends who have 20 year age differences. She's the younger one, incidentally. In the Hansen case she was 30, supposedly. For all I care she could have slept with a 70 year old or a 20 year old, and it would not have been lewd. Subject to gossip, perhaps. But not lewd or news.
Depends on how we define "lewd". Even something which is just "lustful" and "indecent" (simultaneously) can obviously be described as
lewd. Sexual conduct which involves adultery is (IMO) lustful
and indecent. I have to admit that the age gap does not affect to what extent it's lewd or not - I just mentioned it anyway to use Chris Hansen's own rhetorics against him. Same goes for the usage of the word "lewd", which otherwise could be seen as a bit far-fetched to use in this context. It also has to be mentioned, though, that in many countries, Chris and his girlfriend would both be stoned to death for what they may have done.
I actually kinda agree. From the descriptions I've read, his show was an entertainment piece, not news. Relishing in another human's downfall is... um, not nice.

Unless you plan on being perfect for your entire life.
These are examples of sarcasm and diatribe that he used during the Petaluma investigation:
Decoy: So what do you wanna do?
mannbay2004: Let's see how it goes.
Decoy: Ok, so you're playing hard to get, huh?
mannbay2004: M-hm.
Chris:
(coming out from the shelter) Now, let's see how it goes.
Chris: Alright, so 20 years younger than you are. Why prey on somebody who says they’re 13?
a_latino_man_559: I didn’t. I didn’t, sir. I was—I was—I don’t—
Chris: You did— you
did!! You talked to girl who said she was 13. You bought all the stuff. And you came over— Did you bring condoms?
(this last question has formerly been asked by the decoy)
a_latino_man_559: Yeah. They’re—yeah. But, you know.
Chris: Yeah! You just said that a moment ago, so, no reason to
lie about it.