Paul’s ubiquity contrasts with that of some of his colleagues. Marco Rubio, another first-term senator and potential 2016 contender, has intentionally focused his efforts on just four Senate races, in Colorado, Arkansas, Iowa, and New Hampshire.

Rubio’s strategy, says an aide, is to “make a big impact by focusing on a handful of races.” ​That’s why Rubio’s Reclaim America PAC only endorsed four Senate candidates: Gardner, Cotton, Ernst, and Brown. The PAC has spent over $300,000 on Senate TV ads, one for Cotton and one for Ernst, and Rubio will stump with Brown in New Hampshire twice next month.

The divergent approaches say something about how they’ll approach the 2016 race: Paul relies greatly on the force of his personality, which is in great demand, while Rubio is more focused, purposeful, and deliberate.