The promise of Rand Paul's campaign for U.S. Senate was simple to understand. His father, Ron Paul, had spent a long time in the House of Representatives as a lonely "no" vote against... well, almost everything. But the House is a majority-rule body, and individual no votes don't count for much. A senator with Paul's philosophy and total disinterest in being popular could do plenty, threatening filibusters, mounting filibusters, and introducing amendments to change bad bills.
This was what Paul tried to do with the PATRIOT Act reauthorization. There was very, very little doubt that the law would be reauthorized. There was only limited interest in amending it. But most of the amendments came from Paul , who wanted to make a point, and could. And the two amendments he fought to the end for were telling. One amendment would have exempted 4473s, the form gun owners fill out when registering weapons, from PATRIOT provisions. That was bait for conservatives, even though the NRA did not take a position on it. (Saxby Chambliss read the NRA's non-statement into the congressional record.) One would have made it the job of the government, not banks, to initiate "suspicious activity reports." There's broader support for an idea like that -- outside of Congress at least.
In the end, Paul got votes on both amendments. There was no expectation that they would pass. There would be no vote on a more comprehensive Democratic-sponsored amendment; Paul's amendments were the bones thrown to libertarians. That's not a victory, but it's something. And Paul used the occasion to give a genuinely compelling speech about civil liberties.
UPDATE: Both of Paul's amendments failed.