You accurately enumerate several threats to Trump in the Midwest. The farm problem, beyond whether, is plausibly attributable to the trade war with China, that is, China has found a way to drive a wedge between Trump and Midwestern farmers who are vital to his reelection.
Another threat, these mass shootings and the reflexive calls for some limitation of the right to keep and bear arms, provides an opening for Democrats to push a wedge between Trump's rural Midwestern gun owning population and the absolutely vital white, educated, female suburban voter.
A conservative analysis is likely to conclude that on election day it it will come down to a choice between the utter craziness of the modern Democrat party or Donald Trump and all that he represents. Confronted with this choice, Midwestern farmers are conservative enough to forgive some diminution of Second Amendment rights when they look at the catastrophe of Democrat rule. In this analysis, Trump wins again because the Democrats are as bad as Hillary Clinton was.
But this presumes a binary situation in which the electorate votes Democrat or Republican and ignores the very real third possibility, as you perceptibly pointed out in your reply, that Republican inclined voters might simply stay home. Many voters, historically inclined to vote Democrat, stayed home in 2016 and Trump won.
Suburban women did not stay home in 2018 and we lost the house.
A bankrupt Midwestern farmer is not likely to stay home, he simply cannot afford to. I think he will vote for the candidate who most credibly promises salvation. If the Democrats can pin the bankruptcies on Trump and his China policies, game over for his decision. That farmer understandably has become a single issue voter for his very survival.
A disenchanted gun owner on the other hand probably will consider the whole range of consequences of a crazed, runaway leftist president. If Trump holds to his other fundamental contracts with the American people, the wall, no foreign wars, no more dancing with Ivanka, and holds onto his economy, he can prevail with most of them.
That does not necessarily mean that white, educated, suburban women will vote Trump. Just as they do not speak Second Amendment, their worldview is the polar opposite from the Midwestern gun owner. They want everybody to get along but, above all, they want the persons dear to them to be protected. They want the health needs of everyone they love to be taken care of. That means they want total healthcare for their kids and spouse and they want a place to put mama in her dotage. They want protection against chronic and deadly illnesses such as cancer. They want a safe school to put their children in without bullying, certainly without gun violence and, for many of them, a place without life-threatening dodgeball.
Many of them want a president who talks nice. For these women, Donald Trump can fulfill every one of their needs but they will vote against him because of his image.
So where is the greater risk for Trump, failing to appease suburban women by some nod toward gun control a group with whom appeasement might simply not avail anyway, or disappointing Second Amendment supporters? The loss of either group can spell the loss of the presidential election.
As for Midwestern farmers, Trump must explain to the nation what world dominance by China means and he must do so in terms that describe real loss of liberty, not just loss of middle-class comforts. They must go to the polls as patriots. If they do, Trump will have reversed the Democrats' threat and driven a wedge between the modern, crazed Democrat party and their traditional middle-class supporters.
