History of Election Results for Ballot Issues

Overview of the Statewide Ballot Measure Process

Both the Colorado Constitution and state statutes are subject to amendment by legislatively  referred and citizen-initiated measures. The process is governed by the Colorado Constitution  and state law.¹ 

Legislatively referred measures. The Colorado General Assembly may refer constitutional  measures to the voters with a two-thirds vote of both houses, and may refer statutory measures  to the voters with a majority vote of both houses. A constitutional measure requires 55 percent  of the votes cast in an election to pass, except when a proposed measure repeals rather than  changes part of the constitution, in which case a simple majority of votes is required.² While the  General Assembly has the authority to change the state statutes during legislative session, the  Taxpayer’s Bill of Rights (TABOR) requires that proposed tax increases receive approval from  voters in order to take effect. The General Assembly submitted its first measure to Colorado  voters in 1880.

Citizen-initiated measures. Any Colorado resident may place a constitutional or statutory measure on the ballot. To place a measure on the ballot, proponents must collect the number of signatures equal to 5 percent of the total number of votes cast for the Secretary of State at the previous general election. Additionally, to place a constitutional measure on the ballot, at least 2 percent of registered voters’ signatures in each of the state’s 35 senate districts are required. The constitutional measure must also receive at least 55 percent of all votes cast to pass, unless a proposed measure repeals rather than changes part of the constitution, in which case a simple majority of votes is required.3 The use of citizen-initiated measures for constitutional and statutory changes was voted into law in 1910 and became available in 1912.

Process for placing a citizen-initiated measure on the ballot. The multi-step process for placing a citizen-initiated measure on the ballot includes the submission of a proposed initiative; a review and comment hearing on the proposal with the Office of Legislative Legal Services and the Legislative Council Staff; a hearing with the Title Board to set the single-subject title; and verification of collected signatures by the Secretary of State. These steps are outlined on the Secretary of State’s and the Colorado General Assembly’s websites.

Even- and odd-numbered year elections. State law clarifies the types of proposals that may appear on a statewide ballot in odd-numbered years.4 Odd-year election proposals are limited to state matters arising under TABOR. These types of proposals include a new tax, a tax rate increase, an extension of an expiring tax, a tax policy change directly causing a net revenue gain, and emergency taxes. They also include the creation of multiple-year fiscal obligations or debt, an increase in the assessment rate for a class of property, the weakening of a state limit on spending, and voter-approved revenue changes. State law does not limit the types of proposals that are eligible for the ballot in even-numbered years.

Numbering and lettering for ballot measures. Statewide citizen-initiated measures are numbered, while those that are legislatively referred are lettered. Table 1 provides further detail on the numbering and lettering schedule for statewide ballot measures.

Statewide Ballot Measures from 1880 to 2024

The tables below provide information about statewide ballot measures from 1880 to 2024. Table 2 displays ballot measures by type, origin, and outcome. Table 3 classifies measures by category.

Online Colorado Election Archives

The Colorado Legislative Council Staff maintains an online database of statewide ballot measures dating back to 1880.

The Secretary of State’s Office also maintains an archive of election results dating back to 1902. This information is also presented in the form of a searchable database.