For much of the year, Delta's website had a prominent notice warning travelers about incompetent TSA security at GRR:
• Effective immediately, Airport check-in for Delta operated flights departing from Grand Rapids, MI (GRR) has changed. We recommend that you arrive at the airport 90 minutes prior to your scheduled departure time and check in at least 60 minutes prior to departure.
Here's a thread in the Delta forum:
Long Check-In Requirements for . . . GRR!?!?