Proponents of the democratic system touts that it is the best form of government. Yet, without proper checks and balances, the “majority rules” (sadly, only at 51%) can lead to the “tyranny of the majority” towards the rights of the minority. In your projects, there are comparable and ancillary political challenges as well.
Tyranny of the project sponsor: Listen to all stakeholders and keep the project sponsor abreast of various perspectives and their impacts on the project. You may impose but others can always oppose.
Political red tapes: Certain processes such as approvals and reviews take time; incorporate them into your schedule. Be optimistic yet realistic.
Community filibuster: Users may delay the deliverables for pedantic reasons; be politically savvy. Deal with the small pains for the big gains.
At the end of the day, aim for completion and not perfection.