2020 Colorado US Senate Election-Will Gardner(R-CO) be more vulnerable than Heller(R-NV)is in 2018?

[nkpolitics1212]

3. The reason why I brought up Gardner's likely vulnerability is because I have been a resident of CO

couple of months before Gardner narrowly defeated Udall in 2014.
Regarding the 2018 US Senate Election-There are 2 Republican held US Senate seats up in 2018 that are highly vulnerable.
NV-Heller-R and AZ-Flake-R. Democrats are waiting for a top or 2nd tier candidate to run in AZ. On the other hand Democrats are highly vulnerable in IN-Donnelly-D,MO-McCaskill-D,and ND-Heitkamp-D (if Cramer-R decides to run). Democrats are vulnerable but favored to win in FL-Nelson-D,MI-Stabenow-D,MT-Tester-D,OH-Brown-D,PA-Casey-D,WV-Manchin-D,and WI-Baldwin-D.
Democrats could end up with a net loss of 2 seats in 2018.
2020 could be the year Democrats regain control of the US Senate. We need a net gain of 4 seats assuming Trump loses re-election or 5 seats if another Russian hacking occurs in 2020.
Vulnerable Democratic incumbents up in 2020-Peters-MI,Franken-MN,Shaheen-NH,and Warner-VA will benefit from the Democratic Presidential nominee's coattails.
Democrats will pick up CO-Gardner-R,NC-Tillis-R,MT-Daines-R (if Bullock-D runs), ME-if Collins retires or gets defeated in the primary, and AZ-if there is a special election due to McCain's departure. Another scenario is Democrats will pick up CO,NC,IA-Ernst-R and GA-Perdue-R plus Trump loses re-election.