I am not a fan of Thatcher. In many ways I found her too extremist. But I admire her for how she took on the Miners Union. That union more or less had Britain captive to its demands. It took Thatcher a hard fight to defeat it: for months there was not enough coal and the country was seriously hurt. But Thatcher didn't give up and in the end she won. It didn't make her popular either: before the Falkland War her popularity was low. Yet now many see her as a visionary.
Reagan did something similar when he broke the air traffic controller's strike by firing the strikers. In his case there was less upheaval. But when the air traffic had become paralized or the strikers had somehow managed to keep their jobs Reagan would have been seriously humiliated and would have had to struggle not to become a lame duck. A good example what can go wrong is Hillary Clinton. After her failed attempt to introduce universal health insurance she didn't play a political role for quite some time.
I would like to see more such visionaries. Take California. In California the teachers union CTA is what the Miners Union was to the UK. Going far beyong simply defending the basic interests of the teachers it paralizes the education system, blocks reforms, has achieved very poshy working conditions for teachers and tries to influence subjects that have nothing to do with eduction. Schwarzenegger has had some struggles with the union but he never really has tried to break their power. Such would be a hard fight and schools might be closed for months. But it would be the beginning of the end of the political gridlock that paralizes California's politics.
Obama is in the same position. His country is just as much the hostage of special interest group as California. But in his case these are the most difficult ones: financial. Yet it can be done - as Roosevelt demonstrated some 75 years ago. Obama has the right ideas how to attack the crisis and to reform the financial sector. But until now he hasn't picked his fight.
There is one thing that a courageous leader should keep in mind: voters won't appreciate it - at least not immediately. Voters look at results and the immediate results of a struggle are strikes and breakdown of services. It is only later that the economic benefits become visible. After she broke the power of the miner's union Thatcher was highly impopular - until the Falklands War saved her.