Florida Rep. Patrick Murphy won the Democratic nomination for U.S. Senate, beating out fellow Sunshine State Rep. Alan Grayson in an often contentious primary.

Murphy is running for the seat held by Republican Marco Rubio, who was persuaded by national party leaders to seek a second term in order to help preserve the GOP's fragile majority.

The two-term congressman won the support of national Democratic leaders. President Obama, Vice President Joe Biden and Senate Minority Leader Harry Reid have all endorsed him. Murphy has enjoyed the most fundraising success.

But Grayson ran to Murphy's left, as a perennial progressive thorn in the side of the Democratic establishment. He says party leaders are "corrupt" and have thrown liberal candidates "in the garbage."

Murphy has run behind Hillary Clinton in Florida, at least as tested against Rubio. He has faced questions about whether he exaggerated his business record. Grayson, however, had worse problems, such as getting in a reporter's face and dealing with domestic violence allegations (which he denies) that have caused progressive groups to pull their support.

The Rubio-Murphy race will help determine which party controls the Senate after November.