Because for them to respond to your "Hello", that would require they actually listen, in order to hear you answer the phone. Politicians of every stripe, party, affiliation, whatever, are far too busy TALKING to actually listen to anybody...especially a mere voter.
They pretend to listen for a few months every couple of years, just to increase their odds of being sent back to the special-interest feeding trough in DC. Now, if we could force term limits on Congress, maybe they'd be more concerned with doing their jobs instead of palling around with diplomats at parties to secure that cushy ambassador job for after their "retirement" from politics. Oops, sorry, got on my soapbox and didn't realize it.
The truly ironic thing is...a lot of the time they're using a robo-dialer, but have actual people who are supposed to pick up if the call is answered. And then the real person plays you a RECORDED MESSAGE. The human is there just as a spacer in between machines.
Got a call from this number @ 6:14pm 1 Apr. 14, and if they think I'm going to talk to a robo caller then-- April Fool--
dumb A$$. Not going to talk to the first one, their just waisting time.
Got a call from this number. It is a candidate running for office in the state of Georgia. Why is it a Seattle area code? Guess who is not getting my vote.
Just because the phone number is from WA state does not mean the call originated there. Call center phone systems can be set up to send any data the person who set up the system wants to your Caller ID. That's easy. They could have it read "Private" or "Unregistered", and have it return a number from anywhere at all. You could run Voice Over IP at home and select to have the phone number seem to be from any legit area code you choose. The phone number is no longer a reliable indicator of where the organization placing the call actually is.
Back just a few years, it would actually be sensible to have your call center in a state other than the one you were calling people in - as in-state long-distance toll charges were way more expensive that out-of-state long-distance. And unlimited long distance calling isn't always available for commercial ventures, as it is for private citizens.