Drawing electoral districts so that they are compact (e.g., algorithmic redistricting such as bdistricting.com), avoiding gerrymandering, tends to concentrate poor people into a small number of districts because the poor tend to live in high density neighborhoods. (Previously mentioned.) The highest density neighborhoods around the world tend to be slums or housing projects.
In contrast, if a political party whose political base is the poor is in power, they will draw districts so that the poor have a just barely majority in many of them (but winner takes all per district) and consequently dividing and diluting the political influence of their opponents, the rich.
Of course, if a political party whose political base is the rich is in power, things will be reversed.
Which political situation is more likely?
On one hand, the poor constitute the majority of the population, so it seems likely their political party would usually have power. Power would thus usually rest with the majority, so democracy is functioning as designed: tyranny of the minority by the majority will happen, a known hard problem with democracy. Should this hard problem be addressed by regulating the districting algorithm or process?
On the other hand, the rich have tremendous power to influence the political process by financing campaigns and paying for propaganda, so it is also plausible that the political party of the rich would usually have power. However, if this is true, it seems unwise to try to fix the corruptive influence of money on politics by changing the political districting algorithm or process. Better would be campaign finance regulations and a political discourse that helps good speech win over bad speech (deceptive propaganda).
Inspired by Amartya Sen, perhaps the purpose of democracy is not to yield great outcomes but to simply avoid extremely bad outcomes, e.g., famine. It seems that democracy withstands corruption in times of crisis: we can imagine a scenario in which the rich would prefer to let the poor die of famine rather than do income redistribution to aid them, and so the rich apply their financial might to keep or gain political power to achieve this outcome, but their efforts are in vain, because democracy seems to prevent this. What kind of districting allows democracy to continue to function this way?
Compact districts placing the poor into a few districts with high density of poor will decrease the political strength of the poor, who will most likely be the first and hardest hit by crises like famine.