* Jack Lew expected to eventually win Senate backing * Lew: Citigroup bonus was in line with others in industry * Tax reform a focus; Lew shows appetite to tackle it By Anna Yukhananov and Rachelle Younglai WASHINGTON, Feb 13 (Reuters) - Jack Lew, President Barack Obama's pick to be U.S. treasury secretary, on Wednesday fended off criticism about his financial experience and tried to find common ground on tax reform with lawmakers considering his nomination.

She may be fresh out of a job, but Hillary Clinton is currently the most popular political figure in America, well ahead of President Barack Obama, who is slipping, a poll published Friday found. Clinton, who stepped down last month as Obama's secretary of state, enjoys a 61 percent favorability among US voters compared with a 34 percent unfavorable rating, according to a survey by Quinnipiac University. Obama, who beat Clinton to the Democratic nomination in 2008 and took the White House, had a positive-negative favorability of 51-46 percent.

John Kerry seized the reins of US diplomacy on Monday, winning a warm welcome from State Department staff as he took over from Hillary Clinton in what he described as a "homecoming." Proving that "the Foreign Service is in my genes," Kerry brandished a battered copy of his first diplomatic passport, issued at the age of 11 when his diplomat father was posted to Berlin.

(Updates with Kerry statement, paragraphs 4-7) WASHINGTON, Feb 1 (Reuters) - U.S. President Barack Obama offered Senator John Kerry the job of secretary of state a week before Susan Rice, the U.S. ambassador to the United Nations, withdrew her name from contention, the Boston Globe reported on Friday. "He called me, actually a week before Susan got out of the thing," Kerry told the newspaper, offering a timeline earlier than previously reported.