Not when it uses the power of providing financial incentives to influence legislation. There is indeed a fine line between first amendment and illicit influence, but Ted Cruz eloquently explained the difference in how pragmatically lobbyists have breached the barriers between petitioning (legal) and colluding (very illegal). I have to dig up that speech, but I trust Cruz on the constitution far more than 99% of the population.
There are laws against bribery aren’t there? Enforce them.
Don’t restrict people’s employment, in my view that’s not constitutional and would therefore require a constitutional amendment. What do you think Auh?