"We are here to ask President Obama what his legacy will be," Rosi Carrasco said as she climbed down from the "UndocuBus", colorfully painted with butterflies, that the activists traveled in from Arizona.

"What we want to say to President Obama is, on which side of the history is he going to be? Is he going to be remembered as the president that has been deporting the most people in US history, or he is going to be on the side of immigrants?"

Rosi's husband, Martin Unzueta, said:

"I am undocumented. I've been living here for 18 years. I pay taxes, and I'm paying more taxes than Citibank."

The border state of Arizona has become ground zero in the national immigration crisis, with the passage of the notorious SB 1070 law that sought to criminalize simply being in the state without documentation. Such immigration determinations are under federal jurisdiction, and violations of them are actually civil offenses, not criminal. With SB 1070, Arizona pre-empted federal immigration policy, until most of its provisions were struck down in federal court.

While immigrant rights activists consider the court's decision a victory, our nation remains plagued by its broken immigration policy. The Arizona law prompted similar bills in Republican-controlled state legislatures across the country. When a draconian anti-immigrant bill was signed into law in Alabama, Latinos fled east to Georgia and Florida, while Alabama farmers, unable to find hired help willing to do the backbreaking work typically reserved for migrants, saw their crops rot in the fields.

This is where movements come in. When the machinery of government breaks down, when politicians and bureaucrats create gridlock, it takes the power of the people to effect meaningful change, often at great personal risk. Across the US, immigrant activists are increasingly engaging in civil disobedience, especially the young. Just as it was young people in North Carolina more than half a century ago who defied the advice of their elders to be more patient in the fight against segregation, today many young people have targeted President Obama with sit-down actions in his campaign offices, pressuring for passage of the Dream Act. Many of them came to this country as children, without documentation.

President Obama showed some sympathy for these "Dreamers" last June, when he announced a decision within the department of homeland security to free 800,000 of them from the threat of potential deportation proceedings:

"Imagine you've done everything right your entire life – studied hard, worked hard, maybe even graduated at the top of your class – only to suddenly face the threat of deportation to a country that you know nothing about, with a language that you may not even speak … it makes no sense to expel talented young people, who, for all intents and purposes, are Americans – they've been raised as Americans; understand themselves to be part of this country."

Many celebrated the announcement, then challenged the president to act on his pledge. Several activists got themselves detained so they could enter the Broward Transitional Center, a pre-deportation jail in Florida, and interview detainees. They found dozens of people who are eligible for release under President Obama's policies, but who languish in the jail nevertheless.

Here in Charlotte, outside the convention center, ten brave souls, among them a young woman and her mother, a couple and their daughter, sat down in the pouring rain on a large banner they placed in the middle of the intersection. The banner read "No Papers, No Fear" (in Spanish, "Sin Papeles, Sin Miedo"), with a large butterfly in the center.

As the police surrounded them, I asked one of the women about to be arrested, why a butterfly? "Because butterflies have no borders," she told me. "Butterflies are free."

• Denis Moynihan contributed research to this column.

© 2012 Amy Goodman; distributed by King Features Syndicate