Drawing weird district lines to achieve voter suppression is unethical, no matter who is doing it. Creating districts should be non-partisan.
Political districts should be drawn up by non-partisan methods, of which there are several. State Senate District 13 in the Houston area is an example of extreme gerrymandering. The shape was drawn by Republican legislators to make sure that the number of Democratic senators in Austin was as small as possible.
This dilutes the votes of people who tend to vote Democratic, including African-Americans, Hispanics, Asians, immigrants, LGBTQs, environmentalists, and others. When Texas "turns blue", which is just a matter of time, it will be just as inappropriate for the Democrats to do gerrymandering as it is for the Republicans.