The Sixth Amendment guarantees you a lawyer in criminal cases, but the Supreme Court has ruled that lawyer must provide effective assistance—not perfect representation, just performance that meets professional norms. Defense counsel who sleeps through trial, fails to investigate obvious defenses, or misses filing deadlines can get convictions overturned.
The standard comes from Strickland v. Washington: you must prove your lawyer's performance fell below objective reasonableness and that the deficient performance prejudiced your case. In practice, public defender offices are so underfunded that excessive caseloads threaten constitutional adequacy. A 2023 national study found most public defender offices can't keep up with demand, leaving public defenders to choose between triaging cases or giving every client less time than the case requires—both paths toward ineffective assistance.