Endorsement points are gained each time you retire. You can then use those points in the endorsements section to add boosts to your lobbyists and increase your money earning potential. These are also tied to your ideology choice so they will show you different people depending on your main politician. However, you will get the same number of endorsement points regardless of political party.
The endorsements persist through each retirement but you can use the “reset all” button to reclaim the points and re-allocate them to different areas. You do not need to retire to reset your endorsements.