From an article in The Hill by "K Street Insider" Thomas Spulak on best practices for lobbyists giving campaign contributions: "The more time between making a campaign contribution and requesting official action, the better." Timing is, as they say, everything.
The article does note the difficulty in remaining ethically "in the clear" as lawmakers struggle to do their jobs, and raise the millions they need to run to keep their jobs. To Spulak's credit, he mentions several laws that could be enacted to do away with many conflicts of interest this situation creates, including full public financing of campaigns.
To read the list of careful considerations and delicate sidesteps lobbyists must take to avoid suspicion that their campaign contribution is quid pro quo for favorable treatment in Congress, is to understand why incremental bans on certain types of contributions at certain times will never solve the problem the way a public financing program, which does away with the need to collect big contributions from anyone, would. After all, the aim should not be to merely reduce the appearance of a conflict of interest, but to reduce the incidences of such a conflict.
Without that alternative, we're left with this mess:
There is growing concern among lobbyists about the scrutiny their fundraising activities will face from interested parties — such as competitors, public interest groups and law enforcement officials. These groups will examine whether a contribution made to the lawmaker with whom a lobbyist is working was actually a bribe or an illegal gratuity.
Although not the only factor, a prosecutor would consider the timing of when a campaign contribution is made as part of the decision to charge a violation of the bribery of illegal gratuities statute. At what point does making a contribution to a member with whom the lobbyist is working rise to the level of bribery or an illegal gratuity? How long must a lobbyist wait after the requesting or completion of an official act to make a campaign contribution?
Given the fact that Congress is always in session, there are no “timeouts” that could be used as a safe harbor.