However, given what we know about voter demographics and turnout in the United States during "mid-term" elections (low turnout among young people, with much "green field" to expand into)... it's clearly an attempt to influence the election, in the favor of Google shareholders' interest.
I'd cite references, but they are too easy to Google (heh).
It's a shovel all right.
(PS -- don't get me wrong or reflexively downvote me for perceived partisanship -- my party interests align with Google's in this matter, outside of anti-trust issues)
EDIT: to add, Google ran no such Doodle for National Voter Registration day last year, according to their archives. HMMMMM.
General "get out the vote" and "register to vote" campaigns favor the Democrats.
I'm in favor of such campaigns generally, but in this case it's quite self-serving.
...but then again, the Google Doodle I see today is: "register to vote!"
That's clearly an attempt to put a thumb on the scales, against a party and administration that is threatening anti-trust action against Google.
I'm already voting the way Google wants me to, but a shovel is a shovel.