Marine in Congress slams Trump over his Robert E. Lee comments
President Donald J. Trump salutes U.S. Army Maj. Gen. Michael L. Howard. (DoD Photo by U.S. Army Sgt. James K. McCann)

Donald Trump was hilariously mocked by Marine serving in Congress following comments by the former president on the Afghanistan war.

Trump, who is marking the 20th anniversary of the 9/11 terrorist attacks by providing commentary during boxing matches at a Florida casino, sent out a statement to reporters on Afghanistan on Wednesday.

"Robert E. Lee is considered by many Generals to be the greatest strategist of them all," Trump wrote complete with his unusual capitalization. "If only we had Robert E. Lee to command our troops in Afghanistan, that disaster would have ended in a complete and total victory many years ago. What an embarrassment we are suffering because we don't have the genius of a Robert E. Lee!"

But Rep. Conor Lamb (D-PA), who went on to serve in the Marine Corps Reserves after leaving active duty in 2013, offered his thoughts on Trump and Lee.

"I guess Trump & Robert E. Lee both know how it feels to suffer a humiliating defeat at the hands of pro-democracy forces in Pennsylvania," Lamb wrote.

Lamb is running for the U.S. Senate seat being vacated by Sen. Pat Toomey (R-PA), who has announced he is not seeking re-election.

Lt. Gov. John Fetterman, state Sen. Sharif Street, state Rep. Malcolm Kenyatta and Val Arkoosh, chair of the Montgomery County Board of Commissions, are also seeking the Democratic Party nomination.

Trump has endorsed Republican Sean Parnell, although Jeff Bartos is also seeking the GOP nomination and says Parnell is "unelectable."