America's 10 Best Senators

-#include virtual="/time/2006/includes/senators.txt" -->By law, just about anyone can be a U.S. Senator. The Constitution requires only that you have reached your 30th birthday, reside in the state you represent and have held American citizenship for nine years. But if the framers made qualifying for the job easy, they made excelling at it difficult. James Madison called the Senate a "fence" against the "fickleness and passion" of public opinion, and the rules of the place ensure that it is as cumbersome and restrictive as that sounds. Any of the 100 members can try to change, or completely hijack, another member's bill as it comes up for a vote. And any one of them can bring the place to a halt with a filibuster. Mastering a powerful institution that relies on comity but requires confrontation takes a special kind of talent.

Or talents. There is no fixed journey to greatness in the Senate. Instead there is a whole variety of skills that America's Senators have developed over 218 years to help them raise and spend tax dollars, oversee the operation of government and, in the case of the best among them, pass laws that benefit their constituents, their country and the world. Time spoke to dozens of academics, political scientists and current and former Senators to pick the 10 best of the 109th Congress. One made it because he puts unsexy but important issues on the national agenda, another because his backroom negotiating turns conflict into consensus. A third got on the list for his diligent bird-dogging of Enron, Homeland Security and the Pentagon. Then there's the prodigious across-the-aisle dealer, the fierce defender of her constituents and the expert who sees around corners. As with any all-star team, we sought a broad range of gifts rather than settling on 10 great pitchers or middle linebackers.

They say the Senate is the world's most exclusive club. But the real elite is made up not of those who break in but of those who make a difference once they get there. Here are 10 who do.