Sure, some may have faced the minor inconvenience of not eating at their favorite restaurant, but it barely made a ripple on most non-immigrants’ day-to-day lives.

Even worse: Some immigrants were fired from their jobs for failing to show up for work. And, in some places, the protest-related school absences were considered a positive -- such as at one school in Riverside County, California, where the teachers took to Facebook to crow about how awesome it was to have the Hispanic students absent that day.

Alas, the real economic impact of immigrants largely goes unnoticed when it matters most -- at tax time.

If the immigration hard-liners magically got their way and the nation’s illegal immigrants suddenly disappeared, the United States would lose out on an estimated $11.74 billion in annual state and local tax revenue from a combination of sales, excise, personal income and property taxes, according to a tally by the Institute on Taxation and Economic Policy. 

Even in Montana, a state with only about 1,000 undocumented people, their tax contributions are just over $550,000. In California, home to more than 3 million unlawfully present immigrants, contributions total more than $3.1 billion.

According to the institute’s most recent data, “the nation’s estimated 11 million undocumented immigrants pay 8 percent of their incomes in state and local taxes every year. While it is unlikely to happen in the current political environment, undocumented immigrants’ state and local tax contributions could increase by up to $2.1 billion under comprehensive immigration reform.” 

Still unmoved? Well, let’s look at the “Effects of Unauthorized Immigration on the Actuarial Status of the Social Security Trust Funds,” a report published by the Social Security Administration in 2013, which said:

“We estimate that earnings by unauthorized immigrants result in a net positive effect on Social Security financial status generally, and that this effect contributed roughly $12 billion to the cash flow of the program for 2010. We estimate that future years will experience a continuation of this positive impact on the trust funds.”

Most people don’t know this: Though there is no “line” for immigrants to get in for the purposes of entering the U.S. legally, there is a mechanism for paying taxes whether they’re here with valid papers or not.

This mechanism is called an Individual Taxpayer Identification Number, or ITIN, and many illegal immigrants use this method to comply with tax law on the off chance that they may someday get the opportunity to prove to an immigration judge that they have “good moral character” and deserve a shot at legal permanent residence.

In 2010, according to the National Immigration Law Center, over 3 million federal tax returns were filed with ITINs -- all of this with no expectation of ever being able to draw funds from Social Security.

Some people don’t want to hear this, though. 

In the weeks leading up to protests demanding that President Trump release his tax returns, Belen Sisa, who is covered by the Deferred Action for Childhood Arrivals (DACA), posted a photo of her fourth annual tax form and the message, “MYTH BUSTER: I, an undocumented immigrant, just filed my taxes and PAID $300 to the state of Arizona. I cannot receive financial aid from the state or federal government for school, I cannot benefit from unemployment, a reduced health care plan, or a retirement fund.”

The post went viral and, predictably, Sisa was deluged with hate messages on social media, allusions to having reported her to Immigration and Customs Enforcement (ICE), and death threats.

In response, she told NBC Latino that unlawfully present immigrants should “take a picture of your taxes and make a post. Let them know that you pay taxes, too, because people don’t know.”

They really don’t. 

Advocacy stunts, white papers and well-sourced reports are fine, if low-key, methods of showing the value illegal immigrants bring to this country. Perhaps a countdown clock of how quickly the Social Security trust fund will run out of cash without them would be more effective.