Complex sentence: An ally of new Prime Minister Paul Martin, Silva was seen by the party machinery as a preferable candidate to Caccia, the longest serving MP in parliament, whose leftist and strongly pro-environment views clashed with the direction Martin wished to move the party.
Split into simpler sentences: An ally of new Prime Minister Paul Martin, Silva was seen by the party machinery as a preferable candidate to Caccia, the longest serving Member of Parliament (MP). Caccia's leftist and strongly pro-environment views clashed with the direction in which Martin intended to move the party.