By GINGER GIBSON, POLITICO- Rep. Bill Cassidy (R-La.) will announce a run for a U.S. Senate seat on Wednesday, sources confirmed to POLITICO.

The impending announcement that he will challenge Democratic Sen. Mary Landrieu, first reported by The Associated Press, will take place in a video.

Cassidy will then launch an announcement tour in the state, a source also confirmed.

Joel DiGrado, who was Sen. David Vitter’s communication director during his 2010 campaign and was deputy state director for the Rick Santorum 2012 primary campaign, will be managing Cassidy’s campaign, a source with knowledge confirmed.

Vitter’s backing would likely give Cassidy a leg up in the race, particularly if the more tea party-aligned Rep. John Fleming or former Rep. Jeff Landry decided to run.

Many of Vitter’s staff moved over to work on Santorum’s 2012 campaign, which bested Romney by 22 percentage points in Louisiana. Vitter is rumored to be considering a 2015 run for governor, when Gov. Bobby Jindal’s (R) term expires. Having Vitter staff work on the 2014 Senate race would keep the senator’s voter identification records and ground operations fresh if he sought future elected office.

Landrieu has been identified as a moderate Democrat that Republicans plan to target in 2014.

Louisiana does not use a primary system to elect officials. Instead, the state conducts open general elections where any number of candidates can run for office. If no candidate receives a simple majority, the top two vote-getters enter a runoff.

via Louisiana Senate 2014: Bill Cassidy to challenge Mary Landrieu – Ginger Gibson – POLITICO.com.