I'll go with Former Whitehouse Chief of staff to President Obama
- current U.S. ambassador to Japan
- former Senior Advisor to President Clinton
- former White House Director of Political Affairs
- former Mayor of Chicago.
He holds US and Israeli citizenship.
What does the Chief of Staff Do?
The Chief of staff can summon other cabinet officials to the Whitehouse and give them instruction. His words are as if they came from the President. Because they do. The COS's job is to speak for the president in the executive, act for the president, schedule the president, decide which meetings to handle himself and which meetings the President should handle, and make sure all the other cabinet ministers are doing the president's will. No other Cabinet official works as closely with the President, has the same cross over dept authority. No other Cabinet official can even meet with the President without scheduling it with his Chief of Staff first including the VP. If the COS wants to see the President he doesn't have to schedule it, he doesn't have to go through one of the President's secretaries in his outer office, all the COS has to do is open a single door in his office and walk directly into the Oval office.
Unlike any other Cabinet official the Chief of Staff is in on every decision the President makes. He is the President's Senior Advisor, the other 12 senior advisors to the president report to him. He is the most senior political appointee at the White House. In the Trump and Biden Administrations the Chief of Staff sat/sits at the head of the Cabinet table. He sits in the situation room where some other Cabinet officials are absent. He sits on the National Security Council too.
The Chief of staff is literally the #2 guy in any administration. Not the VP, Sec Defense, or Sec of State.
The VP job is a rather weak position. It is as important or unimportant as the President decides. President Kennedy famously gave Vice President Johnson no responsibility in his administration. President Bush Jr gave Dick Cheney great responsibility in his first term and then took away much of that authority in his second term. Typically the VP job is chosen to balance the ticket geographically or politically. Typically the VP is chosen among the President's political rivals, and even if they aren't the VP job is generally a front runner for the party ticket one the President leaves office. They are not necessarily trusted inside an administration, as they can have their own team, agenda, and own political interests.
The Speaker of the house and Majority Leader in the senate are as or more powerful than the COS in government perhaps. The COS is the #2 job in the Executive. In influence, power, authority, and importance at least while the President lives.