Well, it's pretty much confirmed at this point: South Dakota's Democratic Senator, Tim Johnson, will announce his retirement during a press conference on Tuesday. Now get ready for another Johnson to save the Democrats' narrow lead in the chamber.

On Friday, Politico and the Argus Leader reported Johnson would announce whether or not he plans to run again in the 2014 election at a press conference on Tuesday. Both speculated that the 66-year-old chairman of the Senate banking committee would announce his retirement, but didn't have anything rock solid. Lo and behold, today Reuters reports that Johnson will do just that, according to their sources. Johnson never fully recovered from a brain hemorrhage suffered in 2006 that nearly took his life. Johnson's representatives have not confirmed the Reuters report yet.

Johnson's retirement brings the number of new Senate seats that Democrats have to defend in 2014 up to five: West Virginia Sen. Jay Rockefeller, Iowa Sen. Tom Harkin, Michigan Sen. Carl Levin, and New Jersey Sen. Frank Lautenberg have all announced their retirement. Politico describes the Democrats' chances of holding on to Johnson's Senate seat in the 2014 election as "perilous," and perhaps one of the party's biggest threats after protecting Rockefeller's seat, while Michigan and New Jersey are seen as fairly risk-averse. But, still, that's dangerously close to the Democrats' fatal number: six, or, how many seats the party would need to lose to relinquish control of the Senate to Republicans. Losing control would deal the ultimate blow to President Obama's chances of getting anything done in the latter half of his second term. They have enough trouble already with Republicans controlling Congress, surrendering the Senate would be disastrous. 

Thankfully for the Democrats, it seems they have a stacked house of candidates waiting to replace Johnson. Chief among them is actually Johnson's son, Brendan, a U.S. Attorney for South Dakota who the elder Johnson is expected to tout during Tuesday's official announcement. Reuters explains

Political analysts expect Johnson's son, Brendan Johnson, who is South Dakota's U.S. attorney, to emerge as a potential Democratic candidate in the 2014 election. The younger Johnson has not announced any formal plans to seek the Senate seat.

Former Representative Stephanie Herseth Sandlin, who lost a bid for reelection in 2010, is another leading choice to run if the incumbent senator retires.