Resigning amidst a pending ethics hearing, the departure of U.S. Sen John Ensign, R-Nv., gives Senate Minority Leader Mitch McConnell, R-Ky., an open seat to fill on the powerful Finance Committee.Considered one the of most powerful panels in Congress, the committee deals with taxation and other revenue measures, including broad jurisdiction over Social Security, Medicare and Medicaid.Typically, Senate Republicans base their committee assignments on seniority, but there's speculation that the senior senator from Kentucky will pass over ranking member Sen. Jim DeMint, R-S.C., a rival who challenged McConnell on earmarks and in his own backyard when he backed then-candidate Rand Paul over McConnell's candidate in the 2010 GOP primary.Other names being tossed around for the seat are Sen. Johnny Isakson, R-Ga., and Sen. Richard Burr, R-N.C., who appear to have support among the insiders, but the conservative base has been behind DeMint in the past.A McConnell spokesman declined to comment for this story.Ensign resigns effective May 3.