Two ballot issues are in the works for Denver voters. In their own way, each is about immigration.
One is the Extra Terrestrial Commission proposal, which has provided water cooler fodder nationwide. The other is "impoundment II" which seeks to impound any car driven without a license, rather than specifically aiming at undocumented immigrants, as ill crafted "impoundment I" adopted by Denver voters did. Neither is definitively on the ballot yet, but both are in the works.
Of course, the Denver City Council may also put its own measures on the ballot, and it may want to do something to address city budget stresses or other issues.