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Story highlights

South Carolina Sen. Tim Scott will endorse Marco Rubio on Tuesday, two Rubio campaign sources told CNN

Scott has been hosting town hall events with Republican presidential hopefuls over the past few months

(CNN) —  

South Carolina Sen. Tim Scott will endorse Marco Rubio on Tuesday, two Rubio campaign sources told CNN, a potentially significant boost for the Florida senator in the third-in-the-nation voting state.

One of the sources said the two senators would appear together for the announcement, but added that details were still being worked out.

No additional information was immediately available.

The support of his popular Senate colleague is key for Rubio, who is looking to consolidate the party establishment ahead of the South Carolina primary on February 20.

Since state GOP began voting in 1980, all but one of the Palmetto State primary winners – Newt Gingrich in 2012 being the rare exception – has gone on to win the party’s presidential nomination.

Scott, who in 2014 became the first African-American elected to the U.S. Senate from the South since the late 19th century, is the rare Republican with credentials across the party’s factions. He was appointed to his seat after Jim DeMint left the upper chamber to lead the Heritage Foundation in 2013, and is expected to win reelection in a landslide in November.

Over the past few months, Scott has been hosting town hall events with Republican presidential hopefuls.

“He is very popular at home,” fellow South Carolina Sen. Lindsey Graham, who has endorsed former Florida Gov. Jeb Bush, told CNN in October. “He is a man of faith who appeals to the Chamber of Commerce and the tea party.”