Hillary Clinton announces U.S. Senator Tim Kaine as her running mate

Hillary Clinton says in a text message to supporters that she's picked Virginia Sen. Tim Kaine to join her on the Democratic ticket as their party's nominee for vice president.

RELATED: What you need to know about Tim Kaine

In the message, Clinton says: "I'm thrilled to tell you this first: I've chosen Sen. Tim Kaine as my running mate."

Kaine is expected to join Clinton at a rally in Florida on Saturday.

A favorite since the start of Clinton's search for a running mate, Kaine is a former governor of the battleground state and former mayor of Richmond.

Kaine won election to the Senate four years ago after serving as the chairman of the Democratic National Committee.

Clinton is choosing Kaine from a group that included Agriculture Secretary Tom Vilsack and Massachusetts Sen. Elizabeth Warren.