Voter suppression backfires
While a significant part of the Bush-Cheney 2004 election strategy was predicated on keeping voter turnout down in marginal districts in key states, like Ohio, their attempt to affect the Iranian Presidential election with an election-eve statement trashing the entire process seems to have backfired. Even at the time, people were mystified as to why the White House would criticise an election whose procedural flaws are no worse than ones they intend to back in Egypt and Saudi Arabia. And in fact, via the London Times:
Paradoxically, President Bush contributed to [surprise 2nd place candidate Ahmadinejad] ascent with an eve-of-election statement in which he said that the Iranian constitution was undemocratic. The regime spun the message brilliantly, telling Iranians that Mr Bush was ordering a boycott: the public voted in droves as a reaction, giving a 63 per cent turnout that exceeded the most optimistic expectations.
Now, there's always the scenario where the White House actually wanted the hardliner to win and so made their bizarre pre-election intervention with that result in mind. Because the Iranian hardliners have a long history of getting the White House to do what they want -- getting rid of the Taliban and then Saddam, for instance. Not that we think they have a mole in the White House, or anything.
UPDATE: Another article notes the same impact of Bush's statement.