Complex sentence: Committee 2008 is a group of liberal Russian democrats presided by Garry Kasparov opposing president's Vladimir Putin dictatorship, aiming at preventing Putin's election in 2008 and planning to offer their own candidate.
Split into simpler sentences: Committee 2008 is a group of liberal Russian democrats presided by Garry Kasparov opposing what they see as president Vladimir Putin's dictatorship. They are aiming to prevent Putin's possible election in 2008 and planning to offer their own candidate.