Kerry aides insist he's not angling for the job and point to his long involvement in foreign affairs. It started with his famous testimony as a 27-year-old veteran questioning the Vietnam War before the Senate Foreign Relations Committee. It continues today, at age 64, as the No. 3 Democrat on the same panel. But envisioning him in the post would hardly be a stretch given Obama's chances at securing the Democratic nomination, a general election shaping up as a "change" campaign and Kerry's relationship with the Illinois senator. Kerry would likely face competition from Sen. Joseph R. Biden of Delaware, chairman of the Foreign Relations Committee; Sen. Chris Dodd of Connecticut, a former Peace Corps volunteer who also sits on the panel, and former Senate Majority Leader Tom Daschle of South Dakota, a top Obama adviser. Over the weekend, Kerry wrote a Washington Post op-ed column chastising President Bush and John McCain, the Republican presidential nominee-in-waiting, for criticizing Obama after he said that, as president, he would be willing to negotiate with U.S. opponents such as Iran. In recent weeks, the Senate has also passed Kerry-sponsored resolutions seeking humanitarian aid for Burma and Robert Mugabe to step aside as president of Zimbabwe, while Kerry has filed legislation to remove South African President Nelson Mandela from U.S. terrorist watch lists. The senator invited Blair to this island getaway last weekend so they could discuss the Middle East and climate change. "John Kerry would love to end his career as secretary of state. It would be a capstone to a life that has always been devoted to public service, but in particular has been focused on foreign affairs," said Jeffrey Berry, a political science professor at Tufts University. Kerry helped Obama burst on the national stage by selecting the then-Senate candidate to deliver the keynote speech at the 2004 Democratic National Convention. And he endorsed Obama over rival Hillary Rodham Clinton even though she had just won the New Hampshire primary. Yet an Obama spokesman kept a respectful distance from questions about a potential Cabinet appointment. "Senator Obama appreciates his close friendship with Senator Kerry, his service to this country and his early support for our campaign. It is obviously far too early to even speculate about the makeup of an Obama administration â€” as we are still in a nomination fight â€” but with his depth of expertise, especially on issues of foreign policy, Senator Kerry would be on the short list for anyone's Cabinet," said spokesman Bill Burton. Kerry aides recoiled at the question, fearful it would renew criticism the senator has his eyes anywhere but on his homestate constituents. The issue has taken on added sensitivity in an election year in which Kerry faces at least one Republican opponent, and amid questions about Kennedy's health.