> Well, many lobbyists advocate your views by giving money, goods or services to public representatives...

Sure, that's a tactic that happens in lobbying, just as its a tactic that happens in people directly advocating their own views.

I am not saying that lobbying is free of corruption. But the reason the two often go together isn't that lobbying is fundamentally corruption, its that lobbying is an expensive form of petition, which makes its community of users overlap considerably with the set of people/groups with the resources to effectively engage in corruption independently of whether or not they were using an intermediary to do advocacy to public representatives.

It seems to me the truth of corruption versus petition is if the politician sells their vote for cash or actually listens to the merits and makes a decision.

Now that is hard to judge from the outside, but that is the real difference.

I suspect many people believe those in power now are mostly selling their vote for cash not making decisions based on the merit and just happening to side with those giving piles of cash because they heard those people give explanations of why favoring them was a good move for the country.

A few years later it is often not. But politicians can lie legally even if uncovered and documented in lengths afterwards. Funny fact: German president Horst Köhler had to resign from office for saying the truth.

A lobbyist giving money, goods, or services directly to a representative for their personal use would still be corruption. The distinction usually is that you offering to spend money on their behalf for a campaign but if they directly benefit from money or a gift that sort of behavior is usually prosecuted.

> The distinction usually is that you offering to spend money on their behalf for a campaign

Which is also usually corruption and a violation of campaign finance laws which prohibit coordination between unlimited "independent" expenditures and candidates or campaign committees controlled by them.

Any such giving would be a federal crime and happens very rarely.