A New York Times editorial points out: “The vast majority of criminal cases are resolved by plea bargains: 94 percent in state courts, 97 percent in federal. For defendants, accepting a prosecutor’s plea deal is less risky than going to trial and possibly being convicted on a more serious charge with a stiffer sentence.”
The system seems to work … as long as defendants Sixth Amendment rights — that a plea is legitimate only if a defendant has had assistance of counsel while considering it — are respected.