For the time being, the list of Republicans challenging incumbent U.S. Senator Maria Cantwell (D-Wash.) will not grow.

Rumors have swirled for months about a possible run by current Port of Seattle Commission President Bill Bryant, but Bryant made a Monday afternoon phone call to The NW Daily Marker to deliver the news that he is not pursuing a Senate bid this year.

Bryant’s interest had peaked in recent weeks, but there was widespread sentiment among Republican strategists and party officials that an entry this late would require both a massive fundraising effort and a very good explanation.

Though Bryant boasts a strong record on clean water issues, international trade and a personal narrative of bootstrapped success, the memory of Dino Rossi’s late-breaking decision to challenge Sen. Patty Murray still haunts many in the GOP.

Today’s news leaves two Republicans — State Sen. Michael Baumgartner (R-Spokane) and Dr. Art Coday — alone in the race against Cantwell and at this late date it seems increasingly likely one of them will chase Cantwell to the finish line in November.

Former television news broadcaster and King County Executive candidate Susan Hutchison has been persistent on the lips of the political chattering class, but sources close to Hutchison have repeatedly denied that she is looking seriously at the Senate race.