Mass immigration causes problems and raises questions

The border patrol, Homeland security, and all agents on the border changed with protecting the United States stopped once President Biden took over as President of the United States. This mass immigration into the United States has allowed over one million migrants to cross over into the United States and no one knows if they are murderers, rapists, pedophiles, thieves, and child trafficking.Why or what reason did President Biden and Vice President Harris allowed so much in human trafficking and ever source of illegal crime to enter into the United States? I think that all has to do with President Trump doing away with the affordable care act, although arguments have been given that this will help the Democrats get votes, somehow. The question is Susan Rice running the White house for her former boss President Obama?