Rep. Earl Blumenauer (D-Ore.) is one of five members of Congress to have formally recognized Armstrong for his athletic accomplishments, but has remained quiet about the allegations against the cyclist.
The International Cycling Union stripped Armstrong of his seven Tour de France wins and banned him from competition for life on Monday.
Aides to all of these members declined to comment.
In 1991, Blumenauer created the Congressional Bike Caucus, a bipartisan group aimed to promote policies that improve infrastructure and integrate bicycling as a recreational and transportation alternative.
The caucus is supported by over 160 members from 43 different states and the District of Columbia.
The U.S. Anti-Doping Agency (USADA) recently issued a report from 26 witnesses, including 11 former Armstrong teammates, who alleged Armstrong and his teams used a number of performance-enhancing substances during his Tour de France title runs.
Armstrong has denied any allegations of substance abuse, but opted against contesting the USADA findings.