Dan Eggen and T.W. Farnam profile the “rarefied group of millionaires and billionaires acting as kingmakers in the GOP contest.”

“I’m against very wealthy people attempting to or influencing elections,” casino mogul Sheldon Adelson, who is funding a pro-Gingrich super PAC, said in an interview published this week in Forbes magazine. “But as long as it’s doable, I’m going to do it.”

As Benjy Sarlin notices, however, the other side of the coin is that the Republican candidates in general, and Mitt Romney in particular, are having trouble attracting small donors. President Obama, in fact, has raised more from small donors than all the Republicans combined. Here’s the graph:

Sarlin has more here.