2004 Chevrolet Blazer trail Blazer

What you're describing is typical of a worn ignition switch. There's usually three or four different switches built into the one assembly. Arced and pitted contacts cause intermittent operation. Very often heat is generated in worn contacts and that heat will migrate out to the terminals in the connector. Inspect that connector first. If it is melted or you see two blackened terminals, replace the switch, and I'll describe the rest of the repair procedure. You may get by with just the new switch for a few days, but the problem will return if the terminals aren't replaced too.