President Joe Biden alarmed Democratic donors when he leaned on “cheat sheets” while addressing a crowd at a recent fundraising event, RadarOnline.com has learned. While it’s not unusual for Biden, 81, to use notecards — which sometimes include cues on where to sit and stand — donors were reportedly concerned that he used pre-written prompts while speaking with donors at private events. Biden’s fundraising events typically follow the same pattern, which includes an opening statement, often with the use of a teleprompter. Though cameras are not permitted, reporters are present. After opening st…