The 2018 Colorado State Senate elections took place as part of the biennialUnited States elections. Colorado voters elected state senators in 17 of the 35 districts in the state senate. State senators serve four-year terms in the Colorado State Senate. The Colorado Reapportionment Commission provides a statewide map of the state Senate here, and individual district maps are available from the U.S. Census here.
Following the 2016 state Senate elections, Republicans maintained effective control of the Senate with 18 members. Democratic state Senator Cheri Jahn switched from Democrat to unaffiliated on December 29, 2017.[2] However, Sen. Jahn decided to still caucus with Democrats. In the 2018 election, Republicans defended 10 seats while Democrats defended 6 seats with Jahn's 1 Independent seat up for grabs.
To claim control of the chamber from Republicans, the Democrats needed to net 1 Senate seat while electing a Democrat to the Independent seat. The Democratic candidate won the Independent seat while Democrats netted 2 additional seats, giving the party majority status in the chamber. The results ultimately led to Democrats gaining a political trifecta for the first time since 2014.[3]
Heading to the 2018 elections, Republicans held a 1 seat majority in the Senate and sought to defend their very narrow majority in the election. Democrats have not held the state Senate since 2014 and aimed at flipping it to potentially achieve a political trifecta as Democrats were expected to retain control of the state House and gubernatorial nominee Jared Polis was considered the frontrunner heading up to the polls.[4][5]
Five Senate seats were considered vital to determine the political balance of the Senate and even the political outlook of the state. Democratic women dubbed the "Fab Five" were running to defend or win these five competitive districts. Incumbent Republicans Tim Neville and Beth Humenik were seen as the most vulnerable as both narrowly won their races in 2014 and they represented districts in where Democratic presidential nominee Hillary Clinton won in 2016.[4][5]
Democrats handily flipped the state Senate by significantly outperforming their margins compared to 2016 and 2014. Most of the votes that led to the Senate flipping was due to the outsized margins Democratic candidates received throughout the Front Range and ski counties.[3] Independent voters (the largest share of the electorate) along with women voters, younger voters, and suburban voters, helped propel Democrats to victory in many races.[9] Races that were considered competitive but eventally won by the so-called "Fab Five" including Faith Winter, Jessie Danielson, Tammy Story, Kerry Donovan and Brittany Petersen were won by relatively large margins.[10][11] Due to Democrats flipping the Senate, they were able to gain a political trifecta as Democrats expanded their majorities in the state House and won all statewide races, including for governor.[10]
The results in the Senate and other elections throughout 2018 were called by observers a "blue wave" in which Democrats made historic gains in Colorado.[12][9]
