Ron Paul's 2012 presidential campaign represented the most electorally successful run of his political career, winning no states but transforming a fringe libertarian message into a mainstream political force with genuine organizational depth and a passionate base that skewed younger than any other Republican candidate's.

Paul, then 76, entered the race with the same core message he had carried in 2008: end the Federal Reserve, bring American troops home from foreign entanglements, legalize marijuana, and radically reduce the federal government's scope. In 2008, these positions made him a novelty. By 2012, a financial crisis and a decade of unpopular wars had given his critique considerably more resonance.

His campaign demonstrated the power of small-dollar online fundraising before it became standard practice. His so-called "money bombs"—single-day online fundraising pushes that could raise millions—showed what an energized online donor base could produce and influenced fundraising strategy across the political spectrum.

Paul's second-place finish in the New Hampshire primary—with 23 percent of the vote—was his high-water electoral mark. But delegate accumulation through arcane state party processes gave his campaign real leverage at the Republican National Convention, where his supporters demonstrated a discipline and organizing sophistication that surprised the Romney campaign.

His lasting contribution was less electoral than ideological: mainstreaming questions about monetary policy, military intervention, and civil liberties within Republican politics in ways that would echo through the Tea Party movement and beyond.

His son Rand Paul would carry a modified version of that agenda into the 2016 Republican primary.