Kansas City has history and the weight of Congress on its side. President Calvin Coolidge dedicated Liberty Memorial as the national memorial to WWI in 1926. And Congress designated the museum as the official museum in 2004.
Supporters of a national memorial in Washington, D.C., point to the D.C. War Memorial on the National Mall or suggest that Pershing Park adjacent to the White House could be developed as a co-national memorial alongside Liberty Memorial. U.S. Rep. Emanuel Cleaver has been fighting since 2009 to pass legislation that would officially recognize the Kansas City site.
It would be nice if Congress could resolve this issue because memorials aren't something to be bickered over.