Former Pennsylvania Senator Rick Santorum and New York Governor George Pataki joined the six other Republicans seeking their party's presidential nomination this year.
Vermont Independent Bernie Sanders held his formal kick-off this week, as he seeks to win the Democratic Party nomination.
Next week there likely will be at least two more Republicans in the race: South Carolina Senator Lindsey Graham is expected to announce on Monday, and former Texas Governor Rick Perry is expected to announce next Thursday.
Former Florida Governor Jeb Bush and Wisconsin Governor Scott Walker haven't yet set dates for their expected announcements.
Rick Klein of ABC News and Christina Bellantoni of Roll Call discuss the latest in the race for 2016 with Here & Now's Jeremy Hobson.
This segment aired on May 29, 2015.