"To decide the election" means to determine or choose the winner of the election. It signifies the final judgment on who will hold the position or office being voted for. Full definition
This is about empowering real people in the political process and making sure that voters are the ones deciding an election — not the corporations, special - interest groups, or lobbyists. (nystateofpolitics.com)
And it's the people who stay home who often decide an election. (thetyee.ca)
There are reasons for allowing some flexibility in deciding an election date. (totalpolitics.com)