Senate Democratic campaign arm backs Patrick Murphy in Florida

The Senate Democrats' campaign arm endorsed Rep. Patrick Murphy for Florida's open seat, going all in for the conservative lawmaker in what's likely to be a competitive primary.

The Democratic Senatorial Campaign Committee's endorsement may not make a difference to Rep. Alan Grayson, a liberal firebrand who has said he is "probably" running for the seat being vacated by GOP Sen. Marco Rubio.

From the statement issued by Sen. Jon Tester of Montana, chairman of the DSCC:

Patrick Murphy is one of our party’s most promising rising stars, and his track record of fighting for Florida’s working families, seniors, and the environment make him the strongest candidate to win the Florida Senate race and flip this seat. During his time in the House, Patrick has stepped up to protect the Florida Everglades, voted down extreme proposals that would harm Medicare, voted to protect Social Security and fought to ensure that working families are given a fair chance to get ahead. I am confident that Patrick will continue working hard for all Floridians following his successful election to the Senate and we are proud to support his campaign.

Murphy, a former Republican, is only in is second term in Congress. He's already received financial support from Tester and Senate Democratic leader Harry Reid, plus the endorsements of several Florida Democrats in Congress.

The DSCC is defending 10 seats in the 2016 election cycle. The party's Senate campaign arm also has endorsed Ted Strickland, who has a Democratic primary fight in Ohio against P.G. Sittenfeld, and Catherine Cortez Masto in Nevada, who could face an intra-party challenge from Rep. Dina Titus.