Probably Gordon & Schwenkmeyer, a Democratic fundraiser.

I get many calls from Gordon Schwenkmeyer who will not leave a message.

This appears to be a variation on 202-756-9757, reported on 800notes as a political fundraiser. They call me daily or twice daily but hang up if no answer.

See 800notes.com/Phone.aspx/1-202-756-9757

I finally answered this unknown caller. It was a fundraiser for Al Franken, to whom I have contributed. I assured her of my affection for Franken, and that I could not contribute now. I asked my number be removed from their call list. It was all very cordial.