Title 42. How it changed things at the border, and why it’s sparking debate

(CNN) - The Biden administration's plans to lift Title 42 have been raising concerns in border communities and sparking fierce debate in Washington. 

Politicians have been sparring over whether it's the right time to repeal the pandemic public health restrictions.

And a federal judge's decision may have thrown another wrench in the government's plans. 

Here's a look at some key questions and answers about the controversial policy and what's happening on the ground.

Under Title 42, authorities expelled migrants at the US-Mexico border more than 1.8 million times in just over two years, according to US Customs and Border Protection data.

The US asylum system effectively screeched to a halt, with migrants who claimed they were fleeing persecution blocked from making their case -- something that US and international law says they should have a chance to do.

In recent months, the policy drew renewed attention when authorities at first were using it to turn away Ukrainians at the border, then largely started granting exceptions that allowed thousands of Ukrainians seeking refuge to cross. 

Advocates argued a racist double standard was at play as many migrants from Central America and Haiti continued to be turned back under the policy; officials denied that accusation and said each exemption is granted on a case-by-case basis.