A handful of newer Republican members of Congress see endorsing Florida Sen. Marco Rubio’s presidential campaign as something worth stepping out on a limb for, even with a crowded primary field.  

On Wednesday, Rep. Sean P. Duffy, R-Wis., became the seventh lawmaker to back Rubio, telling CQ Roll Call in a statement why he supports the 44-year-old’s candidacy. “There’s no other candidate running who has demonstrated a better understanding of the threats and challenges facing our country than Marco Rubio and it’s why I am proud to endorse him for President. Not only will Marco keep our country safe, he has a plan for a New American Century,” he said. “I look forward to helping Marco win Wisconsin and the GOP nomination.”  

Rubio’s endorsement from Duffy, who was elected to Congress in 2014, comes just weeks after Rep. Darin LaHood, a 47-year-old from Illinois who came to Washington last month after winning a special election, offered his own support.  

The two young Republicans join Rep. John Moolenaar, R-Mich., 54, who was elected in 2014; Rep. Chris Stewart, R-Utah, 55, who was elected in 2012; and Reps. Todd Rokita, R-Ind., and Austin Scott, R-Ga., 45, who were elected in 2010; and Rep. Tom Rooney, R-Fla., 44, who was elected in 2008.  

All of the lawmakers who have endorsed Rubio have been in Congress since he was elected in 2010, and, like Rubio, are younger than age 57, the average age of a member of Congress.  

Rubio trails his rival from Florida, former Gov. Jeb Bush, who has 23 endorsements from members of Congress, according to a CQ Roll Call analysis. Bush, who has been endorsed by senators such as Orrin G. Hatch of Utah and Susan Collins of Maine, has support from a crop of lawmakers and ambassadors who are older and have spent more time in Washington.  

Kentucky Sen. Rand Paul has received 11 endorsements from fellow members of Congress for his presidential campaign, including fellow Kentuckian Senate Majority Leader Mitch McConnell and four of the five Republicans in the state’s House delegation.  

Sen. Ted Cruz, the Texas Republican also seeking his party’s nomination for president, has his own support from the class of 2014 — including Reps. Brian Babin and John Ratcliffe of Texas, and Rep. Jody Hice of Georgia — among his eight endorsements from members of Congress.  

Sen. Lindsey Graham of South Carolina, the other Republican senator running for president, has been endorsed by longtime ally Sen. John McCain, R-Arizona.