They usually show up as "SCF" on caller ID. I called the number back and they claim to be the "National Republic Congressional Committee". The 2nd word of the real organization is republicAN (with an AN at the end). This is similar to the faux calls I get from the "Internal Revenue ServiceS" (note the incorrect plural). I can't believe a real organization would get its own name wrong. I believe this is a scam.
This number calls and calls and does not leave a message. I do not answer calls I do not know. Today I decided to look up the number and now I know from following post. In my opinion even if I answer and ask to be taken off the list it does no good. Therefore I just left my phone ring if I do not know the number.