Communist party under a new name is not Social Democrat.
Then the Republican Party under Bush is no different from the Republican Party whose leaders razed the South to the ground in the Civil War committing some of the worst warcrimes in American history. Personally, as I have no direct experience with Polish politics I will take ms_68's words since he/she is Polish. If he/she says they're a multifactional party, then I'll give them the benefit of the doubt until I have reason not to.