State inmate situations have to establish:
federal issue, usually a Constitutional one
in custody (not necessarily jail, but under some form of restraint .. parole, probation, jail (not fine)
exhaustion of state remedies (you’ve gone all the way up the ladder)
ex.  Batson Claim:  properly raised at trial but lost and convicted; appeal as of right to intermediate appellate court where you lose; now only discretionary review; have to go up all way to highest court (ok if cert. denied … that still counts).
NOW….you can go to U.S. District Court.
“abuse of the writ” – federal court can throw you out for not presenting all issues at once regarding a conviction; best to exhaust ALL of your claims before going to fed court
HC harmless error standard is “whether substantial and injurious effect of influence in determining jury’s verdict” (D has to show error was harmful)