“My assumption is that Josh would have to call to check in,” said a former aide to Mr. Schumer, speaking on background.
“Josh would probably think twice if Chuck was vehemently opposed to the idea,” said another former aide to Mr. Schumer. “My guess is that he’s not and might even like it.”
Mr. Isay, who also counts Michael Bloomberg as a client, and acted as a consultant for Mr. Cuomo in his disastrous 2002 campaign for governor, did not return a call for comment.
On his company Web site, there is one quotation, prominently displayed: “‘If you need television advertising, direct mail or communications advice, I can think of no better place to go.’ —U.S. Senator Chuck Schumer.”
According to an aide to another New York elected official, Ms. Kennedy’s hiring of Mr. Isay sent a signal to all comers for the appointment that “both the mayor and Schumer had to, at the least, not veto it, and at best, which is more likely, are totally on board with it.”
Referring to the mayor, Mr. Klein said, “I know he thinks highly of her.”
Perhaps just as important as who is backing Ms. Kennedy, is who is not standing in her way. Stories at the end of the week evoked the image of the Clintons activating local New York politicians and officials to try and thwart Ms. Kennedy’s candidacy before it launched. But former aides to Mrs. Clinton said those reports were blatantly false.
“The idea that Caroline Kennedy doesn’t have the experience to be a United States senator is as ridiculous as the argument that Hillary Clinton didn’t have the experience to be United States senator,” said a former aide to Mrs. Clinton, who added that, from a tactical point of view, Mrs. Clinton gained nothing from “picking a fight” with Ms. Kennedy.
“It only hurts,” said the former aide, pointing out that any appearance of injecting herself into politics now could endanger Mrs. Clinton’s appointment to the nonpolitical job of secretary of state.
“The notion that Caroline Kennedy is unqualified is ridiculous; she is absolutely qualified,” said Howard Wolfson, the former communications director for Mrs. Clinton during her presidential and original Senate campaign.
Meanwhile, Ms. Kennedy’s actual critics seemed to be regrouping.
In the days preceding the unofficial announcement, she had been mocked by Representative Gary Ackerman as a political J. Lo, Representative Anthony Weiner suggested to Politico that Clinton supporters still held a grudge against her for supporting Barack Obama in the presidential primary, Democratic National Committeeman Robert Zimmerman used the word “dynasty” on CNN, and plugged-in retail workers union president Stuart Appelbaum released a statement calling her a “blank slate.”
It was all enough to prompt Representative Louise Slaughter, who has since endorsed Ms. Kennedy, to remark that her colleagues in the House were reading off coordinated “talking points” and “were trying to get her out of the way.”
Mr. Appelbaum maintained his dismissive tone.
“The sense you get with Caroline Kennedy is that she is at a point in her life when she is deciding what to do with her life after her children have left for college,” he said.
He said that he was “offended that we look for celebrity rather than substance,” and added, “I think the governor has indicated he doesn’t want people campaigning. I don’t know if there is a Kennedy exception.”
Other critics didn’t immediately react to the big news.
Mr. Weiner, who frequently comments, declined. Even before the announcement, Representative Carolyn Maloney, previously the most outspoken candidate in pursuit of the seat, adopted a more restrained line. Representative Kirsten Gillibrand, who one member of Congress called “second only to Maloney” with the verve she has campaigned, has retreated back below the radar.