Why Does is it take Immigration Reform to Protect Immigrants?

I stumbled upon an article written by Laura Murphy, Director of the ACLU Washington Legislation Office.  Ms. Murphy provides a summary of the "highlights and lowlights" of the recent immigration reform legislation that has made its way through the Senate Judiciary Committee.

In reading the summary it struck me that the proposed Senate immigration bill specifically includes protections against the hallmarks of the Obama administration's deportation and detention policy. Such protections include prompt bond hearings for detainees, alternatives to the for-profit privately run immigration detention system, bars to racial and ethnic profiling by federal law enforcement officials, restrictions on the use of solitary confinement, and restrictions on middle-of-the-night deportations.

So let me ask you this... Why does it take a new law to protect immigrants from the discriminatory and abusive practices of the current administration?