In an exclusive interview, Sen. Ted Cruz (R-TX) said Thursday will go do as a “dark day” in Senate history, with Senate Democrats blocking GOP legislation addressing the Islamic State (ISIS) and President Obama’s threat of executive amnesty.

“Unfortunately the Senate Democrats have become an extreme party,” Cruz said in an interview backstage at the Liberty Political Action Conference (LPAC) in Alexandria, Virginia. “They have become a party that has abdicated their responsibilities. Under Harry Reid and the Senate Democrats, we have a do-nothing Senate. There are over 350 bills the House of Representatives has passed and they’re all sitting on Harry Reid’s desk. He will not allow a vote on them.”

The interview with Cruz aired on Breitbart News Saturday on Sirius XM Patriot.

Cruz has introduced two pieces of legislation designed to protect Americans both from U.S. citizens who join the terrorist organization ISIS and from President Obama’s amnesty. The ISIS bill would revoke U.S. citizenship from any American who joins ISIS, a concept that enjoys support from almost everyone in politics, including former Secretary of State Hillary Clinton and Sen. Jeanne Shaheen (D-NH). But when Cruz sought unanimous consent to bring the bill up for debate and a vote, Senate Democrats–through Sen. Mazie Hirono (D-HI)–blocked it.

“So the legislation I introduced was to address this crisis we’re facing with ISIS. ISIS is the face of evil,” Cruz told Breitbart News. “They are crucifying Christians, they are beheading children, they are beheading American journalists–and they have pledged to take jihad back to America to murder Americans here at home. There are roughly 100 Americans fighting alongside ISIS who have taken up arms in jihad against America.”

“The legislation I introduced was legislation that said if you take up arms with ISIS, a terrorist group, you have constructively forfeited your U.S. citizenship,” he explained. “We’re not going to allow ISIS terrorists to come back to this country with a U.S. passport and walk in freely and commit acts of terror murdering Americans here at home. This ought to be an issue that brings everyone together.”

A few years ago, Sen. Scott Brown–who represented Massachusetts in the U.S. Senate but is now running against Shaheen in New Hampshire–introduced a similar bill alongside then Sen. Joe Lieberman, an independent who caucused with Democrats. Brown has hit Shaheen hard on the campaign trail in New Hampshire over the issue, asking her publicly to sign onto the bill. Shaheen’s spokesman, Harrell Kirstein, said in a statement to the Boston Globe earlier this week that Shaheen “believes that anyone who fights with ISIS is a traitor and should lose their citizenship,” but when push came to shove on the floor of the U.S. Senate, Shaheen stood by as her party killed Cruz’s bill. Her office hasn’t responded to a request from Breitbart News about how she did nothing to help the bill.

“If we were dealing in the realm of common sense it ought to be an issue that brings Republicans and Democrats together,” Cruz said. “But unfortunately when I introduced the legislation and asked for Unanimous Consent, the Democrats came out and objected and killed the bill because they’re simply so extreme that they’re unwilling to do anything productive to actually protect Americans. It was a sad day in the U.S. Senate.”

“And I will say, if God forbid we see some of these terrorists come back and carry out some horrific act, this day will prove a dark day in Senate history–when the Senate stood in the way of decisive action to protect the American people,” he warned.

Later on Thursday, during a floor fight that Cruz, Sen. Mike Lee (R-UT), and Senate Budget Committee ranking member Sen. Jeff Sessions (R-AL) led, Senate Democrats banded together to kill another of Cruz’s bills: One that would block the president from granting executive amnesty to millions more illegal aliens, as he says he plans to do.

Cruz, Lee, and Sessions defined a key procedural vote that would have allowed them to force a vote on Cruz’s measure–one that ends the Deferred Action for Childhood Arrivals (DACA) executive amnesty and blocks the president from expanding it. All 45 Senate Republicans voted with them, and five Senate Democrats–Shaheen, Sen. Mary Landrieu (D-LA), Sen. Mark Pryor (D-AR), Sen. Kay Hagan (D-NC) and Sen. Joe Manchin (D-WV)–joined them, leaving them one vote short of being able to force a vote on Cruz’s measure. That theme–that Republicans are so close to blocking Senate Majority Leader Harry Reid and President Obama–looms large heading into the final stretch of this year’s midterm elections.

“It is incredibly close. It is hanging in the balance,” Cruz said. “I believe Republicans are poised to retake the Senate and retire Harry Reid as Majority Leader.”

“The vote today concerned the crisis at the southern border. I represent the state of Texas. I see this every day. It is tragedy. The president is right when he says it is a humanitarian crisis, but it is a crisis of President Obama’s own creation,” he declared. “It is the direct consequence of President Obama’s lawlessness and amnesty. The president has promised the American people he intends to illegally grant amnesty to five or six million more people but just a week ago he told us he’s going to do that but he’s going to wait until after the election.”

Cruz argued that amnesty for illegal aliens is not the right policy because it’s not “compassionate” and that President Obama’s decision to delay his executive amnesty order until after the election is close to if not the most “cynical conduct” he’s ever seen.

“Now I got to say, we’ve seen a lot of cynical conduct in Washington but that ranks really near the top because what he’s saying is he recognizes the American people don’t want amnesty–and that by the way cuts across party lines, that’s Republicans, Democrats, Independents, Libertarians–amnesty is the wrong policy. It’s not compassionate. It’s not consistent with rule of law,” Cruz said. “He recognizes the American people don’t want amnesty so he simply says he’s going to do it but not until after the election because he thinks the American people aren’t paying attention enough to understand he’s made this election a referendum on amnesty.”

Instead of standing against the president’s planned executive amnesty, though, Cruz noted that Senate Democrats stood in the way of efforts to block it. That, Cruz said, is the message he has for voters heading into November: to prevent Obama’s amnesty plans, Americans need to vote for Republicans to unseat Reid from the seat of Senate Majority Leader.

“The Senate Democrats had the opportunity to stand with me and to stand with the House of Representatives,” Cruz said. “I introduced legislation in the Senate to prohibit President Obama’s amnesty. The House of Representatives stood up and led. It took the legislation I introduced and it passed it. But the Senate Democrats stood as one uniform block and said ‘no, we will do nothing to stop amnesty.'”

“In my view, it makes the decision very easy for the American people,” he stated. :If you support amnesty, you should vote for the Democrats. If you support rule of law, if you don’t want to see the president illegally and unconstitutionally granting amnesty to 5 or 6 million more [illegal immigrants], the direct thing you can do is work between now and election day to defeat Senate Democrats and to retire Harry Reid as Majority Leader.”