Sen. Tim Johnson (D-S.D.), chairman of the powerful Senate Banking Committee, is expected to announce today that he will not seek re-election in 2014, the Wall Street Journal reported today. His expected decision to retire could buoy Republican hopes of taking back control of the Senate. A decision by Johnson to step down also could trigger a race to take the gavel of the Senate Banking Committee, which oversees Wall Street, housing and transportation issues. Sen. Jack Reed (D-R.I.), the second-ranking Democrat in the Banking and Senate Armed Services panels, is next in line for both committees and would likely have the option to choose which one he prefers.