It's good for the US to have economically prosperous neighbors too.
In GDP per capita Mexico ranks in front of 120 other nations, including: China, Turkey, Brazil, Argentina, Thailand, and just behind Russia. US imports are 1/3 of their economy; we're running a $100 billion trade deficit with Mexico, which is to their benefit. As an American I'm happy that we're doing that, it's to our benefit that Mexico's economy advances. It has the 15th largest economy in the world and continues to gradually climb. That's despite the intense domestic chaos they've been dealing with there the past ~13 years. As a developing nation their long-term economic potential is immense.