In order to build a political party, you need money: to print posters, to maintain political campaign, to run for elections. That's what ANY POLITICIAN does, so if Lieberman is to be investigated - ALL political parties must be investigated. No political party is "holier" than the others.
U.S. Senate blocks Republican move to defund Planned Parenthood (Reuters)
from the article: AG plans to charge Lieberman with fraud and money laundering