Bush: He's a Bush, so he's got connections. Sally Bradshaw, chief of staff when he was governor, is his go-to political person.
Christie: Republican Governors Association chairmanship allows him to grow his national profile with voters and party officials with regular travel and key appearances. Began building broad coalition of donors through his national fundraising tour in spring 2013. But the shadow of the traffic scandal still hangs over his shadow campaign.
Cruz: Has leadership PAC, Jobs Growth and Economic Freedom. Has been one of the largest beneficiaries of Jim DeMint's Senate Conservatives Fund and has gotten millions of dollars and grassroots logistical support from the Club for Growth, FreedomWorks and Ending Spending PAC. Heritage Action PAC helped sponsor Cruz's summer anti-health-law trip around Texas and country.
Jindal: Created Washington-based nonprofit, America Next, in October 2013 to push policy ideas nationally. For executive director, tapped Jill Neunaber, who worked on Romney's presidential campaign in Iowa and New Hampshire. In March created PAC to help conservative candidates.
Paul: Has formidable leadership PAC called Rand PAC, has maintained ties to father's political network in early primary states and benefits from strong tea party support. Is starting to build teams on the ground in most states.
Perry: Created Americans for Economic Freedom PAC in fall 2013 to raise his profile again, help him test the waters and broadcast ads promoting Republican leadership around the country. Group used more than $200,000 left over from the PAC that raised millions for his 2012 campaign.
Rubio: Beginning more aggressive travel to early voting states; has lagged potential rivals on that front. Ramping up in other ways, too: Shuffled his staff and directed political resources of his Reclaim America PAC to three big Senate midterm races this year, one of them the GOP primary in Iowa.