Cotton's victory is a much bigger deal than you probably think. His election is a significant step for the future of GOP foreign policy, and thus perhaps for American foreign policy.
Cotton, you see, is the golden child of the Republican party's hawkish establishment. He still calls the 2003 Iraq invasion a "just and noble" war. He's young — just 37 — and fervently backed by some of the most influential conservative figures in the nation. His Senate victory makes him a serious candidate for an even higher office some day. But even before then, his ascent could represent a larger movement in his party's foreign policy.
This sets him on a collision course with the GOP's other leading young voice on foreign policy: Sen. Rand Paul. One of Paul's top priorities is moving the Republican Party away from George W. Bush's neoconservatism; one of Cotton's is pulling the party back towards it. And given the slate of immediate foreign policy issues facing the Senate, the two are likely to be at odds sooner rather than later.