Johnson will announce plans Tuesday

Tim Johnson is coming home to make his announcement.

It’s very difficult to not see this as a retirement speech from the most successful politician in South Dakota history. Johnson, 66, is widely expected to say he will not seek a fourth term in the Senate.

His communications director, Perry Plumart, told me Friday night that Johnson will make his announcement in South Dakota on Tuesday. Full details will emerge on Monday, Plumart said, but Johnson talked to Politico today.

Johnson served two terms in the stat House, two in the state Senate, five in the U.S. House, and he is in his third term in the U.S. Senate.

His health, since that traumatic incident more than six years ago, and a poll that shows him trailing both former Gov. Mike Rounds and Rep. Kristi Noem, are surely part of his decision process.

Will his son, U.S. Attorney Brendan Johnson, try to replace him in the Senate? Will former Congresswoman Stephanie Herseth Sandlin run for the Senate? Will they end up in a contested primary, or will one run for the Senate and the other for the House?

The conjecture has been raging for months, and it heated up this past week. On Tuesday, Tim Johnson will make his plans clear.