Sen. Chuck Schumer (D-NY) tore into conservative critics who have sought to exploit the Boston bombings to delay immigration reform, eliciting a strong rebuke from Sen. Chuck Grassley (R-IA).

“The American people are overwhelmingly in favor of immigration reform,” Schumer noted during Monday morning’s hearing before the Senate Judiciary Committee, “The Chairman has a very open process to review ways to improve the bill offer an amendment when we start markup in May and let’s vote on it.” He then sought to dissuade lawmakers from using the events of last week to slow walk the bipartisan bill proposed last week by the Gang of 8, but his comments were met with anger from the Republicans on the committee:

SCHUMER: I say that to those pointing to what happened, terrible tragedy in Boston as, I would say, an excuse for not doing a bill or delaying in many months or years.

GRASSLEY: I never said that. I never said that!

SCHUMER: I never said you did, Sir.

GRASSLEY: I didn’t say anything about delaying the bill.

SEN. JEFF SESSIONS (R-AL): Mr. Chairman, I don’t appreciate –

SEN. PATRICK LEAHY (D-VT): Let me finish. We are going to have probably the most open process on this. It will be debate in the committee, we will have time for it.

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During a hearing on Friday, Grassley argued that “[g]iven the events of this week, it’s important to understand the gaps and loopholes” in the immigration system. “While we don’t yet know the immigration status of people who terrorized the the communities in Massachusetts, when we find out, it will help shed light on the weaknesses of our system.”

Lawmakers part of the so-called Senate Gang of 8 are pushing back against conservatives who are trying to exploit the Boston bombing to slow down the legislative momentum for immigration reform. On Friday, during the Senate Judiciary Committee’s first hearing on a new bipartisan immigration proposal, Sen. Chuck Grassley (R-IA) said that “[g]iven the events of this week, it’s important to understand the gaps and loopholes” in the immigration system and Rep. Louie Gohmert (R-TX) suggested that reform should primarily focus on securing the borders.

But during an appearance on CNN’s State of the Union on Sunday, Sens. Lindsey Graham (R-SC) and Chuck Schumer (D-NY) argued that the Boston incident should motivate lawmakers to expedite the immigration debate, as immigration reform bill offered by lawmakers would close dangerous loopholes in the existing system:

GRAHAM: But in terms of immigration, I think now is the time to bring all the 11 million out of the shadows and find out who they are. Most of them are here to work, but we may find some terrorists in our midst who have been hiding in the shadows. When it comes to the entry/exit visa system. The 19 hijackers all students overstayed their visas and the system didn’t capture that. We’re going to fix that… So we are addressing a broken immigration system. What happened in Boston and international terrorism I think should urge us to act quicker, not slower when it comes to getting the 11 million identified. [...]

SCHUMER: And in fact asylum, which the Tsarnaev family came here on was greatly toughened up a few years after. They might not have gotten asylum under the present law.

Schumer added that the leading opponents of the Gang of 8′s bill “can make any amendments they want.” “And we go to the floor any one of the hundred senators could pose amendments,” he said.

During a separate appearance on Meet The Press, Sen. Dick Durbin (D-IL) — another member of the group — added that “there are four specific provisions in this immigration reform bill that will make America safer,” noting that the measure will bolster security along the southern border and institute a system of employment verification.

Key lawmakers involved in ongoing bipartisan discussions on a comprehensive immigration reform bill signaled optimism on the Sunday morning talk show circuit, with Sens. Chuck Schumer (D-NY) and Jeff Flake (R-AZ) — two members of the Senate’s “Gang of Eight” negotiators working on the reform bill — telling NBC’s Meet The Press that a bill could be introduced as soon as next week in light of a tentative deal on guest worker programs struck by the U.S. Chamber of Commerce and the AFL-CIO.

“With the agreement between business and labor, every major policy issue has been resolved on the Gang of Eight,” said Schumer. Flake was a little more cautious, stressing that senators still have “a ways to go in terms of looking at the language and making sure that it’s everything we thought it would be,” but that they were “closer, certainly.” Sen. Lindsey Graham (R-SC) echoed those sentiments on a separate appearance on CNN, stating that business, labor groups, and the senators themselves have reached a “conceptual” agreement that still needs some details to be filled, but that a bipartisan deal “will be rolled out next week.”

Disagreements over the guest worker program were one of the last remaining sticking points in negotiations between business and labor groups. Under the tentative deal struck Friday, the U.S. would issue anywhere from 20,000 to 200,000 guest worker visas annually, with the number of visas issued in any given year “to grow and shrink according to economic needs.” According to the New York Times, the number of guest workers allowed in to the country would “increase as the nation’s unemployment rate fell and the number of job openings increased,” and a federal commission would be established to “assess the need for guest workers, with an eye to shortages in specific industries and communities.”

Labor and business groups also reached a tentative agreement on wage levels for guest workers, with negotiators agreeing that “guest workers would be paid the prevailing industry wage previously used in the guest worker program.”

Resolving the guest worker issue provides a much-needed boost to Senate efforts, as bipartisan negotiators had already reached agreements over other challenging aspects of a comprehensive immigration reform bill, including border security and a pathway to citizenship for undocumented immigrants. But despite the senators’ optimism, the politically-charged nature of many of the bill’s provisions could present snags as actual legislation works its way through the committee process. On Saturday, Sen. Marco Rubio (R-FL) — another Gang of Eight member — urged caution against moving too fast to pass legislation, taking exception to Senate Democrats’ push to get a bill onto the full Senate floor as fast as possible. In a letter sent to Senate Judiciary Committee chairman Sen. Patrick Leahy (D-VT), Rubio suggested that he would slow down upcoming immigration legislation by calling for committee hearings on the issue.