I think lobbyists don’t pose all that much of a challenge. Americans are just used to corruption being ingrained in the political regime, but that’s due to the moral failings of so many of your elected officials.

It is, however, a lot of power in one chair - in the end of the day you need to trust your advisers and cabinet. If you lack experience in the job even more so. And if they are not competent and aligned with your interests, they might fall for lobbyism more easily.