A nice crowd of about 600 gathered at the Gulfstream Race Track near Ft. Lauderdale Wednesday night to hear me speak. Drawn by a promotion by my local radio affiliate, 850 WTFL, they were fans. Indeed many were intimately familiar with my decades of work on television. Transplanted New Yorkers who relocated to the Sunshine State to avoid winter and high taxes, many had followed me since the Eyewitness News days of the 1970's, or the skinhead brawl and 'Al Capone's Vault' debacles of the 1980's.

In terms of the big picture, the Boston bombings impacted the immigration debate in several ways.

- Geraldo Rivera

But familiarity aside, most had no patience for what I said that night about the need for immigration reform.

Following the terrorist attacks of 9/11/01, I argued, Americans did what we have always done when faced with a profound threat from abroad. We closed ranks and moved to close our borders. Although the attackers were Islamic extremists, primarily Saudi Arabian, our Southwestern border with Mexico was the frontier most affected by the security measures we took to protect against the external threat.

A vastly expanded Border Patrol was recruited and deployed. The border fence, which had been a casual affair, is being replaced by something resembling the Berlin Wall. So even though the 9/11 attackers were Middle Eastern, I argued, and despite the fact that there has never been a confirmed penetration of our southern border by Islamic militants, it was along the Mexican border where the anti-terror hammer fell hardest.

It fell on the migratory farm workers, gardeners and baby sitters. It fell on the transitory poultry processors and meat packers; the seasonal ranch hands and the small factory workers who for generations had been part of a vast informal migration, coming and going across the porous border with Mexico in an informal ebb and flow of humanity that had everything to do with supply and demand and nothing to do with terrorism.

Then I shared my fear with the crowd gathered at Gulfstream Park that America's undocumented immigrants were again being made the scapegoats.

"Good," shouted one middle age woman in the crowd before I fully explained the point. "Send them all back," heckled an elderly man on the other side of the auditorium.

Mildly surprised by the intensity of the anti-immigrant sentiment, I continued undaunted. This time, I told the crowd that the proximate cause of delay in implementing immigration reform in the Senate was the Boston Marathon bombings. Once again, we were attacked by the foreign-born, by immigrants, and that slender thread had been seized by opponents to stymie progress on reform. “So what?!” shouted another gentleman in my Gulfstream audience. “We don’t want them anyway,” added another, a senior citizen who must have been well past the fear that an immigrant might steal his job.

In terms of the big picture, the Boston bombings impacted the immigration debate in several ways. In the Senate, it has fueled a wave of proposed amendments to the compromise bill carefully crafted by the “gang of eight” senators who have toiled for months. While many proposals were rejected by the Judiciary Committee considering the bill, two amendments were accepted, both closing loopholes in the student visa program. The amendments were designed to prevent illegitimate students like the dropout Kazakhs who allegedly helped the younger Boston bomber clean up his dormitory room from over-staying their visas.

Among the amendments rejected, was a proposed $25 billion biometric system that would have tracked undocumented immigrants and other foreigners entering and exiting the country. In all, about 300 amendments have been proposed, and as of Thursday just around 60 had been voted on.

Assuming it survives the Judiciary Committee and the full Senate passes the landmark legislation, the harder test will be in the House of Representatives, where Republicans have vowed to tear up the nearly 900-page compromise bill.

Using Boston and ‘amnesty’ as rallying cries, a significant group of conservative House Republicans have vowed to “rise up” against the bill, and defeat all efforts at comprehensive reform. Mobilizing allies in talk radio and cable news, they stress the need for even greater security along the southern border, and propose dumping comprehensive reform legislation for piecemeal expansion of visas for high end immigrants only. Anything beyond that token easing of restrictions they say is not only amnesty, but a threat to national security.

“They have a gang of eight,” Representative Steve Stockman (R-TX) told one reporter, “We have a gang of millions.”

Hundreds from his gang were in my audience Wednesday night at Gulfstream Park. But to show it was nothing personal they hung around for photos and autographs afterwards.

Geraldo Rivera is currently a Fox News Senior Correspondent.