Is the Sixth Amendment Right to Effective Assistance of Counsel Violated?

The issue is whether individuals convicted in state court can present new evidence in federal court that their trialr was so incompetent. The sixth amendment requires states to appoint a competent, effective lawyer for indigent defendants who cannot afford one. But what happens if the state appoints to you a crappy lawyer who doesn't raise arguments in your defence or investigates the evidence against you? How and where are you supposed to argue that your sixth amendment right to the effective assistance of counsel was lated? That typically doesn't happen on your appeal.