Yeah no. Opposing a complete waste of taxpayer money is not the same as supporting the destruction of our southern border. There isn't a single Democrat in Congress who wants an open border. Many of them support tighter security along the border, and most just want a more efficient way of processing applicants.
As for your question, it's not even worth answering. It makes about as much sense as asking, "What would happen if we gave handguns to every citizen over the age of 6, regardless of criminal history or mental health?". It's not going to happen, like EVER, so it amounts to baseless fearmongering.
If you support the wall, fine, cool, whatever. I disagree with you, but you're entitled to your opinion. Don't say stupid stuff that's not in any way true.