Who does this who mean?

It was an hones description of his position, and, though the audience could not know it, of this earm's posture in the talks at the hotel. Ford wanted substantive promises about substantive matters-nothing less. " For me to go there and go through the ceremonial aspects, it wouldn't be fair to Betty, it wouldn't be fair to me, it wouldn't be fair to the president, and it wouldn't be right for the country," Ford told Cronkite. " So I have to, before I can even consider any revision in the firm position I have taken, I have to have responsible assurances."

Cronkite asked about the " question of pride," as much for Ford as for Reagan, who, as Cronkite said, would be taking on a vice presidential running mate " who ... has said,'It's going to be something like a copresidency'?"

1) --taking on mens undertake ( so having the power to choose the candidate)?

2) In this phrase' who..has said', whom does this who mean?