The Trump Administration has escalated U.S. military attacks against forces associated with the Syrian government - without Congressional authorization. Under the Constitution, such military actions should not happen if they have not been authorized by Congress.
The U.S. military engaged in strikes against pro-government forces on May 18, June 6, and June 8, and shot down armed Iranian-made drones in Southern Syria on June 8 and June 20. On June 18 a U.S. fighter aircraft shot down a Syrian SU-22 bomber, marking the first time the U.S. has downed a manned Syrian aircraft in the course of the Syrian conflict. On June 26, the White House released a statement threatening further military action against the Syrian government.
The key to preventing U.S. military escalation in Syria is getting Members of Congress to speak up in writing against it. In 2013, U.S. military escalation in Syria was prevented because Members of Congress signed letters insisting that President Obama come to Congress for authorization before taking military action.
Congressional Progressive Caucus Vice Chair Rep. David Cicilline [D-RI] is circulating a letter to President Trump demanding that Trump stop escalating in Syria without Congressional authorization.
Urge your Representative to join the Cicilline letter by signing our petition.
On April 6, President Trump attacked Syria without Congressional authorization, violating the Constitution and the War Powers Resolution. On April 8, he said he would take additional action as he deemed necessary. He has not yet agreed to seek Congressional authorization before further military action.
Representative Zoe Lofgren [CA-19] is circulating a bipartisan letter to President Trump, demanding that he seek Congressional authorization before further military action in Syria. The Lofgren letter echoes a bipartisan 2013 letter led by then-Republican Representative Scott Rigell to then-President Obama, pressing him to come to Congress before U.S. military action in Syria. 
Urge your Representative to support the Lofgren letter by signing our petition at MoveOn.