The thing to remember with Ron and Patti is that they were never one to speak for their father. They were in fact estranged from him. Patti actively worked against her father in protests and books and such. I believe I've heard of Ron's liberal politics too. They are nothing like their father and DO NOT SPEAK FOR THEIR FATHER. And that was a disgrace to use his funeral for a political attack. Patti and Ron will never change. Michael is his father's son. Maureen was his daughter too. As for Nancy, let's hope she doesn't betray her husband's memory in using it to attack this President and push for a stem cell research using his name in which he was strongly pro-life.
I doubt that Nancy is going to be put in that position, though Ron and Patti are probably twisting her arm. She knows that all Bush need do in response is say:
"Nancy, your husband led this country through the courage of his convictions, all based on deeply-felt moral decisions. Would you ask me to do less?"