Which Democrat will challenge U.S. Sen. Cory Gardner? Four names sit on top of insiders' lists.

The 2018 election results aren’t official yet, but minds are already turning to Colorado’s next big electoral contest: U.S. Sen. Cory Gardner’s 2020 re-election bid.

Given the mood of Colorado’s electorate in 2018, the Republican’s chances appear at first blush to be grave. And Gardner’s critics piled on again after the chairman of the National Republican Senatorial Committee defended Republicans’ objections over vote counting in Florida on “Meet the Press” on Sunday. However, a lot can happen between now and Election Day 2020, including a Democratic primary election that will pick Gardner’s opponent.

There is no shortage of potential challengers, political watchers said this week. However, four names are on top of most lists: Colorado House Speaker Crisanta Duran, former state Sen. and gubernatorial candidate Mike Johnston, U.S. Rep. Ed Perlmutter and Gov. John Hickenlooper.

“The field is very much in flux, and there are a lot of conversations to be had,” said Craig Hughes, a Democratic campaign strategist who helped U.S. Sen. Michael Bennet win his first election in 2010. Hughes also ran Johnston’s gubernatorial bid.

Read more: https://www.denverpost.com/2018/11/14/cory-gardner-senate-re-election-democratic-challengers/