The situation at the border is better than it has been in years or decades. Fewer apprehensions, better fencing, more border patrol, doing a better job - there is no emergency. Trump himself said that the Southern border has been secured by him.
On the other hand, there are fewer white people in the country. For racists, that is the real emergency, and reason for all this chaos.
Also, this isn't about illegal immigration. The Trump administration is going after legal immigration - wanting to stop family-based immigration, end TPS, the RAISE act, etc, and more recently and more high profile ending the different ways asylum seekers can come here (which is legal, not illegal). For Republicans it's legal immigration that's the current target.