Here’s an example of gerrymandering - Texas 7th Congressional District:
The Texas districts map was last updated in 2012 by the ruling Republicans. Although in some states maps are drawn up by bipartisan commission, election outcomes are often skewed by these weirdly drawn districts, designed expressly to reduce Democratic voters to a minority in as many districts as possible.
Rep. Zoe Lofgren (D-CA-19) has introduced H.R. 1102 Redistricting Reform Act of 2017 which would mandate that states conduct redistricting through independent commissions.
If your MoC is one of the co-sponsors of the bill, contact them to say thank you. If your MoC is not one of the co-sponsors, contact them to ask that they get on board. House contact info: www.house.gov.