Yes, ignition switches can be out of alignment and can fail; wires can push out of the harness connectors, wire strands inside the insulation can fracture from oxidation. First use a jumper from an ignition switched source (wiper motor, etc) to be sure it solves the problem. Then disconnect, and trace back or forward until you find where the power goes away.

Start at the coil + and with the ignition switch on, you should have a reading of about 9-10 v in reference to engine ground (not coil - ). Then trace back to where that wire comes out of its bundle and goes into the bulkhead connector. With a test light, should be voltage there. If not, go inside the car and test the ignition tap on the fusebox relative to ground. If no power there, check the ignition switch, horn relay, fuses, fusible links, and wiring for defects.