If Rupert Murdoch or Bill Gates were running for President, then, yes, their past politiccal stances would matter.
The people here asking questions about Trump’s political past ask the same questions about a lot of candidates and appointment nominees.
Stop playing the victim card.
Nobody is saying Trump is an ideal conservative.
OTOH, Cruz supporters insist he is the only Principled Conservative (TM) in the race and are totally incurious to anything that might go against that dogma.