Amendment 41 bans lawmakers from accepting anything of value from lobbyists and sets a $50 limit on what lawmakers can accept from others who are not lobbyists.
The state's high court reversed a temporary injunction against the ethics law, ruling it was too soon to claim the First Amendment rights were violated, The Denver Post reported. A five-member panel that will hear alleged ethics complaints is not even in existence yet.
"This is the second win for the voters. They won in 2006 and they won again (Monday)," said Jenny Flanagan, director of Common Cause, the group that backed the constitutional amendment.
Challengers to the ethics law said they were disappointed the Supreme Court did not provide clarification about how the measure should be interpreted and enforced.
Four of the ethics panel's five members have been selected. A complaint awaits the panel when it's seated -- an allegation against Secretary of State Mike Coffman filed by Colorado Ethics Watch.