Should Trump contest Illinois?

[ηєω ƒяσηтιєя]

Yes, he should waste his time in a Safe D state.

[fluffypanther19]

He has a very narrow window of opportunity for winning the 2020 election. At this time I see  Michigan  and Pennsylvania more 'lost' than Wisconsin and Iowa (the two states usually vote together, and either one of Iowa and Wisconsin basically wins for the Democrat with either 272 or 278 electoral votes. Picking off New Hampshire also wreaks havoc on the Democratic nominee. No Democratic nominee for President has won without winning New Hampshire since 1976, and I expect that to hold in 2020.

Trump will have to spend 20 points on the Kill and 80 on defense.  That corresponds to the number of electoral votes of Wisconsin (10), Iowa (6), and New Hampshire (4) together. It is safe to assign points for the Kill as the electoral voters of those three states and concede Michigan, Pennsylvania (costly media markets) and anything else that Trump barely lost.  He's not going to win Minnesota while losing Wisconsin, and he can win Nevada but still lose the election.

He has far too much to defend to try making the Kill anywhere other than Iowa, New Hampshire, and Wisconsin. That leaves 80 for defense, and he will need it all. If he makes a quixotic bid for Michigan or Pennsylvania he might get blindsided by Florida.

Florida kills his prospect of a second term if he loses the state. Arizona is next-closest, and those two states combine for 40 electoral votes. Then North Carolina, at 15. Each electoral vote of each state is as important as any one of those in the other two states, and to those states I would have to allot 55 points corresponding to their electoral votes:
 
Florida 29
Arizona 11
North Carolina 15.

That leaves ME-02 (forget it!), NE-02 (to reach western Iowa he will need to use Nebraska media, so that is a bonus from allocating resources to Iowa) to which I would add no additional resources.

Does anyone want to allocate 25 points to Ohio, Georgia, and Texas? Let's put it this way: if he is at risk of losing Texas he has lost anyway because Texas straddles the 400th electoral vote for a Democratic nominee, as it has since 1984.  Likewise, if he is losing Georgia, he is losing North Carolina.  18 points go to Ohio, and Montana isn't looking so great for him. The remaining 4? He may need to defend Utah from a Third-Party or independent conservative alternative in the event that Utah Democrats decide that their nominee for President cannot win. Ouch!

In summary, 

Defense:

FL 29
AZ 11
NC 15
OH 18
MT 3
UT 4

The Kill:

WI 10
IA 6
NH 4

He can forget Maine, Michigan, Minnesota, Nevada, and Pennsylvania.

Trump wins Illinois and Washington around 400 electoral votes for the Republican, and we all know that that is not going to happen except in a rigged election.

lol thank you for the time and effort you put into this

[blacknwhiterose]

Here's an interesting map tracking the President's approval ratings by state:
https://morningconsult.com/tracking-trump/

I wouldn't equate all the negative approval states as lean-Democratic though.  For the same reason pollsters misinterpreted the 2016 pre-election polls, there may be a shy-Trump supporter factor, plus a lot of people voted Trump despite disliking him.  Take for instance Utah: he's a -1 disapproval rating there on account of his unpopularity with socially conservative mormons and evangelicals - but come election day these voters aren't gonna break for a pro-choice socially liberal Democrat.  Utah is safe Republican, but I've got it lean/pink on my map anyways:

https://www.270towin.com/presidential_map_new/maps/vvgk0.png

According to my calculus, Trump would need all of the pink states plus either Pennsylvania or a combination of Wisconsin and Nevada, to win re-election.

And to answer OP, no, of course he should not waste his time on Illinois.