“They” had predicted that this election would make history in Alberta.
“They” had predicted that the new Wildrose Party would win, and take over from the Progressive Conservatives (PCs), who have held power there since 1971.
“They” were wrong.
“They,” are the pollsters; the people who take polls. They ask people, prior to an election, how they intend to vote and make an educated guess as to who will win an election.
Most of the polls predicted not just a win for the Wildrose Party, but that the Wildrose Party might get a majority as well.