Mr. Kennedy, who is running for president as a Democrat, said that he would sign a ban after three months’ gestation, but his campaign quickly reversed his comments.
The presidential bid by Robert F. Kennedy Jr. has tested the bonds of an iconic Democratic clan that does not want him to run and does not know what to do about it.
A super PAC backing Robert F. Kennedy Jr.’s bid for the Democratic nomination received $5 million from a major Republican donor who has supported Donald J. Trump in the past.