While the Senate-passed comprehensive immigration bill languishes in congressional purgatory, states are moving forward in passing progressive immigration reform laws. 

So far, 437 immigration-related bills have been passed by Republicans and Democrats in 45 state legislatures across the country, The Washington Post reports. 

"We are still waiting for the federal government to fix the immigration system," said Rep. Sharon Tomiko Santos, D-Wash., the co-chair of the National Conference of State Legislatures' immigration task force. "States are doing the best we can with the tools we have available to us. State legislators face fiscal challenges in education, health and law enforcement. To do nothing is not an option."

While many red states tightened immigration laws after the Supreme Court struck down some elements of Arizona's controversial immigration bill, SB 1070, a bunch of Democratic-controlled states--and even some that are Republican-controlled--have passed laws that are beneficial for undocumented immigrants. 

Advocates for immigrants rights said they are happy with the progress states are making on immigration reform. The National Immigration Law Center wrote that states "witnessed a significant increase in pro-immigrant activity" over the past year. "States led the way by adopting policies designed to integrate immigrants more fully into their communities."

"The blue states are out in the front, adopting a wider range of measures," said Tanya Broder, a senior attorney at NILC and one of the authors of the report.

However, she said that legislators are also sponsoring tuition and license bills in Virginia and Pennsylvania, where the GOP controls at least one chamber of the legislature. "There are Republicans who are responding to the growing political power of [immigrant] communities," Broder said.

Yet, many Republican-controlled states, such as Georgia, Alabama and Indiana, passed legislation in 2012 that was similar to Arizona's tough anti-immigration law. All five laws are subject to ongoing litigation. But the challenges to the laws and the possibility of comprehensive reform passing in Congress has slowed the passage of anti-immigraiton measures. In 2013, only Georgia passed new laws changing the E-Verify program for employers and redefined eligibility for public benefit programs. 

Many anti-immigraiton advocates are worried about the future. 

"We're going to see ... really a surge of immigration legislation at the state and local level," said Bob Dane, a spokesman for the Federation for American Immigration Reform, an anti-illegal immigration group. "And the reason is, is because it's really precipitated from the top down. You've had five years of the Obama administration systematically dismantling interior and perimeter enforcement [and] gutting the laws."

Conversely, Democratic-controlled states have allowed students who are undocumented to pay in-state tuition at state-run colleges, and Colorado, Minnesota, New Jersey and Oregon have expanded in-state tuition access. Fifteen states have passed so-called "tuition-equality" laws. 

California has led the pack in immigration reform, including measures that prevent local law enforcement from handing over undocumented immigrants for deportation if they are arrested for minor crimes. The state also allows undocumented immigrants to be admitted to the state bar, and passed a law that protects immigrants from harassment in the workplace. 

In 2013, 10 states, ranging from liberal states, like Vermont and Oregon, to more moderate states, like Maine and Nevada, to pass driver's license bills for undocumented immigrants. A similar law passed in Washington, D.C. and will soon be reviewed before Congress. 

"We seem to go through these waves of different kinds of legislation," said Ann Morse, author of the NCSL report on immigration laws. The focus on driver's licenses "reflects the changing attitude in America about young immigrants who are here without making the choice to be here."

"These kids are trying to go to school and will need to drive and will need to work," Morse added.

Only five states--Kansas, New Hampshire, Montana, Delaware and Wyoming--did not pass bills related to immigration in 2013. 

More states are likely to act on the driver's license bills this year, and at least seven state legislatures, including Massachusetts and Mississippi, are considering tuition equality bills.