If groups that advocate changing immigration law to create a path for the nearly 11 million illegal immigrants in the United States to become U.S. citizens get their way, today could be the biggest day of coordinated protests in the country's history.
They're calling it the National Day of Action for Immigration Justice.
"It's by far the biggest public statement on immigration policy on one side or the other that we've ever seen," said Roberto Suro, director of the Pew Hispanic Center.
At least 136 rallies are planned in 39 states today, all aimed at encouraging the U.S. Senate to pass its bipartisan immigration reform bill.
"If these demonstrations today prove as big as suspected," Suro said, "it's going to increase the pressure on the Senate to come back and address this issue again."
The turnout at demonstrations around the country over the weekend surprised local officials. Police in Dallas estimated that as many as 500,000 people had marched there, and tens of thousands showed up for demonstrations in Salt Lake City, San Diego and other cities.
The opinions expected to be expressed at today's rallies are diverse.
Yanira Merino is an illegal immigrant who says she came to the United States to give her children a chance at a better life.
"If I had had the opportunity to stay in my country, most likely, I would be in my country," Merino said. "But if I was hoping for a better future for me and my children, I needed to look for something better. My country was not giving that to me."
But people like Michelle Dellacroce, of Mothers Against Illegal Aliens, feel that American children are adversely -- and unfairly -- affected by this kind of illegal immigration.
"They're not happy with what they have in their country. They want to come here illegally and then put their children into our schools so that we pay for their children's education and that needs to stop," Dellacroce said. "My taxes pay for the education for my children to go to that school. My children should be learning the education in the public schools in English, not in two separate languages."
Senate leaders announced they had reached a compromise on the bill on Thursday, but then it fell apart on Friday. Lawmakers, however, say the issue is not dead.
"I think tempers will cool over a two-week period," Sen. Arlen Specter, R-Pa., told The Associated Press. "And also, there are going to be some expressions by many people very unhappy with the Senate not passing a bill and very unhappy with the House bill" that would make coming into the United States illegally a felony. It is currently a misdemeanor.
The estimated 1 million protesters expected to march today plan to make their side of the story difficult to ignore.
ABC's Claire Shipman and Heather Nauert contributed to this report.