Plea for Power

• WWizards of the Coast2014-05-29
  Official Ruling
  You must vote for one of the available options. You can't abstain.
• WWizards of the Coast2014-05-29
  Official Ruling
  Players can't do anything after they finish voting but before the spell or ability that included the vote finishes resolving.
• WWizards of the Coast2014-05-29
  Official Ruling
  No player votes until the spell or ability resolves. Any responses to that spell or ability must be made without knowing the outcome of the vote.
• WWizards of the Coast2014-05-29
  Official Ruling
  Because the votes are cast in turn order, each player will know the votes of players who voted beforehand.
• WWizards of the Coast2014-05-29
  Official Ruling
  The phrase "the vote is tied" refers only to when there is more than one choice that received the most votes. For example, if a 5-player vote from among three different choices ends 3 votes to 1 vote to 1 vote, the vote isn't tied.

Rulings via Scryfall