$10k will get you access, but you won't convince a politician to do something that will cost them all of the other $10k checks they get from special interests.

Like if you wanted to buy a senator in order to get some earmarks for your development projects, you could probably get that buying a table at a fundraiser or two. But if you want them to pass legislation supporting unions or reducing the influence of money in politics, you'd basically have to bankroll their whole campaign because they wouldn't raise another dime.