That’s a pretty common and easily fixed condition. You can buy a tool to align, or make your own like I did using a piece of square steel pipe from the hardware store, a scrap axle and some spacers.
To use, remove the RD, thread the short end of axle in the hanger, and snug things up so the pipe just turns freely. Then move it around the wheel and measure to the rim. Use the tool as a lever to gently bend the hanger as necessary until the hanger and rim are in parallel planes.
