Two years ago today, Arizona's Gov. Jan Brewer signed into law a bill known as SB 1070. Already, the strict anti-illegal immigration bill had caused heated debate in and out of Arizona, most notably because it would make it a misdemeanor to lack proper immigration documents in the state - and because it would empower local police to check for immigration status if they had “reasonable suspicion” that someone was in the country illegally.

Back then, I wrote about the broad implications that SB 1070 would likely have. Would there be a political ripple effect, with other states considering similar laws? Would some immigrants decide they'd had enough and leave the state? Would it change the political discourse on immigration, with politicians basing their platforms on strict policies? And if tested in court, would it hold up?

Two years later, the answer to most of those questions is a resounding yes. Save for the latter one, to be decided soon enough as SB 1070 heads to the U.S. Supreme Court this week.

In the relatively short time it has existed, SB 1070 has had a profound effect on the immigration landscape, politically and in human terms. Although four of its most controversial provisions (including the "reasonable suspicion" checks) were blocked by a federal judge in Phoenix in July 2010, just before it went into effect, the law's implications have been broad indeed.

Here are three aspects of SB 1070's legacy so far:

1) The ripple effect in the states

Since 2010, dozens of states have introduced their own anti-illegal immigration laws, some modeled directly after SB 1070 and written with the help of the same legal counsel. SB 1070-style laws have been enacted since in Alabama, Georgia, Utah, Indiana and South Carolina.

These new laws are just part of what’s been happening in other states. The National Conference of State Legislatures reported late last year that in 2011, there were 1,607 bills and resolutions relating to immigrants and refugees introduced in all 50 states and Puerto Rico, up from a little more than 1,400 in 2010. Bolstered by the relative success of SB 1070, immigration restriction-minded legislators in many states banded together to introduce new crackdowns.

Many bills went nowhere, but there were some bold ones introduced, including a series of bills last year intended to end birthright citizenship for the U.S.-born babies of undocumented immigrants that was introduced in states like Arizona, Indiana and Iowa. Also voted down was an Arizona “omnibus” bill to deny public services to undocumented immigrants, similarly to what California’s ill-fated Proposition 187 proposed in 1994, and an Arizona bill requiring that hospitals check for patients’ immigration status.

In the states that have enacted SB 1070-style laws, all of these measures face their own court challenges. Federal judges have blocked several of these laws’ most stringent provisions, including a controversial one in Alabama that would require public schools to check the immigration status of students.

In some of these states, judges are waiting to see how the Supreme Court rules on SB 1070. The justices are to weigh whether SB 1070 is in fact preempted by federal immigration law, as the federal government has challenged. If the high court decides that enforcing immigration law is strictly a federal task, it could take the air out of the other state measures; it not, it would empower state legislators to continue with these and similar state laws.

2) "Attrition through enforcement"

Long before Republican presidential candidate Mitt Romney made his famous remark about “self-deportation,” immigration restriction advocates had a term for the idea of making life so difficult for undocumented immigrants that they leave the country voluntarily, called “attrition through enforcement.” It was one of the pillars of SB 1070, a concept championed by Kris Kobach, the Kansas secretary of state and attorney who helped draft SB 1070 and similar laws.

In Arizona's case, has the self-deportation idea worked as intended? Some reports indicate that SB 1070 has prompted many to move, though it's unclear where people are going. Recent Homeland Security data estimated that the undocumented population in Arizona has decreased by about 100,000 since 2009; meanwhile, Mexican census numbers show more people returning from the U.S. And in Georgia and Alabama, many immigrants from Latin America have left the state after SB 1070-style laws kicked in, prompting an agricultural labor shortage in both states.

How much is self-deportation, and how much is it undocumented immigrants moving elsewhere in the U.S.? Studies by the Pew Hispanic Center, which each year tracks the estimated undocumented population, have shown that this population has declined significantly since 2007, when it peaked at around 12 million, and that net migration from Mexico has now come to a standstill, as reported today. Factoring into the decline in illegal entries have been the poor U.S. economy, border enforcement and rising deportations. Yet the same time, among those already here, Pew has also found a growing share of undocumented to be staying long-term.

In any case, the uprooting that has occurred is real, regardless of the destination. A recent story from NPR's Fronteras Desk profiled a woman who moved to New Mexico:

Jossie and her family lived in the Phoenix area in 2010, the year Arizona's legislature passed the bill. A federal judge blocked the most controversial parts of SB 1070, including a provision that would require police to check the immigration status of those they believe are in the country illegally.

But that injunction didn't matter for Jossie. She was so nervous driving to work as a housekeeper that she once hyperventilated and lost consciousness on the road, she said.

"New Mexico offer me opportunities," Jossie said.

3) Tougher, bolder political discourse on immigration - and bolder opposition

The back-and-forth continues over just what Mitt Romney meant earlier this year when he called Arizona "a model" for immigration policy, a statement that was first interpreted as praise for SB 1070. His campaign has since said that Romney was praising a different Arizona law, one from 2007 requiring employers to verify new employees' work authorization.

Whatever he meant, the fact that Romney was praising a state immigration law is a telling sign of how state immigration laws like SB 1070 have affected the political discourse. In the aftermath of SB 1070's passage, in spite of its being partly hung up in court, the immigration discourse veered sharply to the right as many conservative state legislators were emboldened to act.

For a while, some of the state measures being introduced topped SB 1070 in terms of how strict they were. Among them were several bills introduced last year, most based on model legislation, intended to outlaw birthright citizenship by reinterpreting the 14th Amendment of the U.S. Constitution. While talk of doing away with automatic citizenship at birth has long existed on the fringes of the immigration debate, after SB 1070, it became mainstream.

In an interview with Multi-American shortly after he and a coalition of other conservative state lawmakers unveiled anti-birthright citizenship model legislation last year, Rep. Daryl Metcalfe explained the thinking at the time:

“The success that Arizona had at the state level and the light that has been shined on their efforts…that does create momentum, that does encourage state legislators who think ‘Hey, if Arizona can do it,’” Metcalfe said. “We’re seeing momentum build."

The broader political effect was perhaps best put into words by former Arizona state senator Russell Pearce, who sponsored SB 1070, in an first-person essay he penned for Politico last November after he was ousted in a recall election. He wrote:

This issue has now become bigger than me — and bigger than Arizona.

We have inspired other states to take action. More than 34 states are now proposing legislation modeled on SB1070. Alabama, South Carolina, Utah and Georgia have already passed bills.

Before I introduced SB 1070, Arizona political luminaries like Sen. John McCain and Rep. Jeff Flake were leading sponsors of amnesty for illegal immigrants. But since we passed it, most of our GOP congressman and senators at least give lip service to supporting patriotic immigration enforcement.

But as seen with the recall of Pearce, who may run for state office again, there has also been a backlash. While SB 1070-inspired laws had traction in some states that saw rapid growth in their immigrant populations in recent years, especially in the South, many similar bills elsewhere have failed to make it into law. Even the stricter post-SB 2070 bills that followed in Arizona, like those opposing birthright citizenship, failed to make it through the statehouse.

Meanwhile, the same year that SB took effect, a movement of young immigrant activists began to see exponential growth, by year's end helping push the nearly decade-old Development, Relief and Education for Alien Minors (DREAM) Act to as close to a win as it's ever gotten in Congress.

While the proposal to legalize certain undocumented young people hasn't moved since, Republicans are now considering a stripped down version as they try to woo Latino voters. And some, including the Mitt Romney campaign, have realized that in an election year, too much talk of strict immigration enforcement can cost necessary votes.

Next stop for SB 1070 is the Supreme Court, which will ultimately decide to what degree states can set their own immigration agenda. Oral arguments are set for Wednesday; a decision isn't likely until June.