Republican lawmakers have approached the U.S. Secret Service with concerns about security issues at July’s Republican National Convention in Milwaukee, Wisconsin, but Secret Service has so far been unwilling to compromise, sources told the Daily Caller. “We have identified a critical flaw with the Security Perimeter that creates an elevated and untenable safety risk to the attending public,” counsel to the Republican National Committee Todd R. Steggerda wrote to Secret Service Director Kimberly Cheatle in April. The current Secret Service plan designates Père Marquette Park as the protected Fi…