Who, among the politicians and rulers of modern times can be considered a good student of Machiavelli's teaching? Can we blame or condemn this person for his or her actions?

Some historians have actually called him Machiavellian, but Richard Nixon is a good example of following Machiavelli's teachings.  One of the most famous quotes attributed to Machiavelli is "The ends justify the means."  Nixon promised "peace with honor" in Vietnam and promised to extricate the American military from the country, yet he authorized the invasions of Laos and Cambodia by Special Forces in order to interdict the Ho Chi Minh Trail.  Nixon also undercut the popularity of those on the Left by authorizing Earth Day, establishing OSHA, and giving money to the humanities.  He also increased federal funding to cancer research.  By adopting these policies of the Left, Nixon had bipartisan appeal.  Nixon's downfall was that he was too Machiavellian--he was distrustful and he knew a great deal about the spying against the Democratic Party headquarters.  Still, Nixon enjoyed a long political career and was able to (mostly) steer between being loved and hated in American politics.