the trump administration says adding the question will help better protect americans under the voting rights act. democrats make the argument that if fewer people respond the next congressional reapportionment won't be accurate. non-citizens tend to live in democratic leaning areas. if fewer of them respond to the census, congressional lines could be redrawn in a way that hurt democrats. there are 107 congressional districts where more than 10% of the population are not u.s. citizens. 21 are held by republicans. all of those democratic districts are considered safe by our friends the koch political report. if non-citizens aren't counted, there could be fewer of the safe democratic districts. 13 of the 21 held by republicans are rated as battleground. if you don't count non-citizens, the lines could get redrawn to include more reliable republican voters. it's unclear how big of an actual political impact this could have or if president trump is interested in simply a rhetorical debate over a policy debate. changes in the census may not