Lobbyists aren't handing over wads of cash, they are spending money on things like ad campaigns, surveys, studies, talks, busing people in to talk to their representative, etc which are meant to legitimately sway the opinions of both the elected officials and the electorate. Maybe to get more politicians to show up the lobbyists pay to serve nice steak dinners at a talk, and in the extreme maybe the talk is just a thinly veiled guise for what is really an expensive gift of steak dinner, but conceptually it's no different from any other potential catering option, and there is no simple way to ban it. Sure you can make specific schemes illegal, but there will always be another loophole. So long as you allow people to interact with their elected representatives and speak freely, there will be people who have their politician's ear. You might be able to eliminate lobbying by sequestering the politicians throughout their term, but that's going to have the opposite of the desired effect of making government more democratic.
If you want to call lobbying 'bribery' in a sort of exaggerated way, go ahead.
In my experience most of the rhetoric around bribery is reapoy just interested groups doing regular politics stuff--like 'if you do not support bill xyz we will tell our million newsletter subscribers you're a bad person'.
And it’s very clear that at least people in congress are very happy with this situation.
Outlaw PACS/Super PACS.
Ban politicians from holding seats on corporate boards for 10 years following serving in any office, except they be returning to a board they already were on. (End revolving door/jobs).
Ban companies from donating at all to all elections.
Require news networks to supply free ads for candidates w/ equal airtime or ban all political ads period (I'd love this one). Let people get picked by merit of their debates alone.
I think the parties should also hold their primaries on the same day nationwide, so there's no 'game' or 'sport' it's just flat out - vote and be done with it, to the victor goes the spoils (the rest of the campaign$$ each candidate has amassed.
We also need ranked choice voting so that 3rd parties can have decent sway ...diluting the current duopoly and making it so interested parties and special interests if allowed would have to work harder and spend more to more parties to get their point across.
There's probably a slew of other things you could do. Of course this requires people in power to take away their own power...like that's gonna happen.