Despite expressing serious misgivings about President Obama's Iran nuclear deal, Senate Democrats have repeatedly blocked a vote opposing the agreement. In doing so, they deny Americans the right to have their voices heard in a debate with far-reaching consequences.

According to a new CNN/ORC poll, a majority of Americans do not believe Iran will make good on its promises. Fifty-nine percent disagree with the President's handling of U.S.-Iran relations. This is hardly unmerited criticism. Iran's Ayatollah Ali Khamenei has made no secret of his ill will toward the state of Israel, saying it will not exist in 25 years. A deal with the world's biggest exporter of terrorism – led by a regime that still shouts "Death to America" and cooperates with North Korea on ballistic missiles – deserves our utmost scrutiny and caution.

Heeding the Lessons of History

I recently outlined my concerns on the Senate floor, suggesting that the disastrous history of the Munich agreement offers an instructive lesson today. A famous quote often credited to Mark Twain puts it this way: "History doesn’t always repeat itself, but it does rhyme."

In 1938, four European leaders forged the Munich agreement, in which Hitler promised not to make war in exchange for control of part of Czechoslovakia. Afterward, one of the agreement's negotiators, British Prime Minister Neville Chamberlain, announced triumphantly that there would be "peace for our time." His optimism, however, was short-lived. Hitler soon annexed the rest of Czechoslovakia and set his sights on Poland and beyond.

Winston Churchill correctly predicted that the Munich accord would lead to war rather than prevent it. One wonders what he would say about today's agreement. The Iran deal has been reached over the objections of Israel, one of our most steadfast allies. It has left our Sunni Arab friends in the Middle East mystified and dismayed, many of whom had hoped for a stronger anti-proliferation agreement.

Billions for Iran Plus Conventional Weapons

The Iranian regime has demonstrated again and again that it is not trustworthy. And yet, the lifting of sanctions in the President's deal offers Iran a $100 billion economic stimulus and access to deadly conventional weapons and ballistic missiles – not to mention the continuance of its nuclear program. I have joined 57 of my colleagues in demanding that the President do better for the American people. The President and Secretary of State John Kerry repeatedly said that no deal is better than a bad deal, but they have given the American people a bad deal.

The stakes are too high merely to hope for the best and have faith in Iran's promises. Alan Dershowitz, a Harvard law professor emeritus and expert on the Middle East, described it this way in his book "The Case Against the Iran Deal": "Hope is different from 'faith,' though neither is an appropriate basis on which to 'roll the dice' on a nuclear deal that might well threaten the security of the world." Instead of allowing the President to roll the dice, we should heed the warnings of experts and the lessons of history, rejecting this deal before it is too late.