The difference between good politicians and also-rans is an impeccable sense of timing; when to be brave, when to pull in your horns, when to hunker down, and when to strike.

For ambitious politicians, there is also the sense of when to move up. Representative Paul Ryan has surveyed the political landscape for 2012 and decided to wait on running for higher office.

National Journal:

Ryan began informing close friends of his decision Tuesday and is expected to announce later in the day. Three GOP sources tell National Journal as soon as Ryan officially announces he won't run for the Senate, former Wisconsin GOP Gov. Tommy Thompson, is expected to announce his candidacy for the Senate seat being vacated by Democratic Sen. Herb Kohl, who recently announced he was retiring.

Thompson, who served as President George W. Bush's Health and Human Services Secretary, has told GOP officials in Wisconsin and D.C. he intends to run if Ryan passes up the open Kohl seat. Ryan has made it clear in recent days he prefers his perch as chairman of the House Budget Committee -- where he believes he can influence, if not drive, the debate on fiscal policy -- to a seat in the Senate.