For example, among Jeb Bush donors, Rubio has raised substantially more money than any other candidate (except Bush, of course). Rubio has also raised more than other candidates from donors to Carly Fiorina and Lindsey Graham—other campaigners in the “mainstream” lane.
To explore another example: Fiorina’s campaign raised about $4.5 million in itemized donations (out of $8.5 million total) through the end of September, according to Federal Election Commission filings. Rubio’s own donor rolls include over $484,000 in contributions from people who also gave to Fiorina; no other candidate got more than $364,000 from Fiorina donors.
Rubio is also in a dead heat with Bush for secondary support from John Kasich donors, too, with each raising about $110,000 from the donor pool that gave $4.4 million ($3.7 million of it itemized) to the Ohio governor.
Meanwhile, Cruz is the other candidate of choice among donors to a large group of candidates from the “insurgent” wing of the GOP. No candidate has raised more from Ben Carson donors (besides Ben Carson) than Cruz, who has raised at least $628,000 from Carson’s pool of donors this year. And the same is true of donors to Mike Huckabee, Bobby Jindal, Rand Paul, Rick Santorum, and Donald Trump, all of whom gave more money to Cruz than to any other candidate besides their own.