If we step back a moment from the government shutdown – an assault on millions of federal workers and people who need the services of the national government at this time – and the Republicans' over-hyped and largely empty threat to trigger a default on the national public debt, there are more significant recent political developments that will continue long after this damaging political theater is over.

President Obama was twice defeated last month on matters of national and international importance, by grassroots opposition and resistance from within his own party. The first was over his planned bombing of Syria; the second was over his attempt to appoint Larry Summers as chair of the Federal Reserve.

The blocking of the Syria bombing was a historic victory with profound implications, perhaps the first time in the past 50 years that the American people were able to prevent an announced military intervention by pressuring Congress. Although some politicians and media outlets tried to say that Obama's military threats led to the agreement on Syria for destruction of its chemical weapons, the exact opposite is more likely true.

Obama had no military threat when he entered into negotiations over Syria – he clearly didn't have the votes in Congress to approve it. And so, he turned to diplomacy, which, for Washington, is all too often a last resort.

The antiwar movement and the American people can also claim credit for the recent and vitally important diplomatic overtures with Iran: despite Obama's continuing, illegal threats that "all options are still on the table", the military option carries increasing political risk at home. The public has become progressively more aware that our endless wars and military interventions have little or nothing to do with so-called "national security".

The defeat of the Summers nomination was also unprecedented, in that a president's choice for Fed chair was rejected because of populist opposition. Summers played a major role in the deregulation and regulatory failures that contributed to the Great Recession, the Asian financial crisis (and resulting US trade deficit), and various abuses of America's bloated, corrupt financial sector.

It has taken a few years, but this is the base of the voters that brought Obama to power asserting itself. When Obama appointed his first cabinet, you could almost hear the collective groan of disillusionment from the millions who made up the mass movement that elected him. There was Goldman-Sachs (Tim Geithner) at Treasury; Bush's defense secretary was held over; and Hillary Clinton as secretary of State. Change seemed mostly down the toilet, and hope was not far behind.

Ironically, the Tea Party Republicans who are holding the government hostage want to get rid of Obamacare, the one really important reform that the president did deliver – even if it was much reduced from what his supporters rightly demanded. The Republicans' desperation has some logic to it; most Americans don't yet appreciate the improvements in health insurance that have been won, but they will as the law is implemented.

The Republicans are fighting a losing battle – and the shutdown will almost certainly increase their losses.

But looking ahead, the more significant contribution of the Tea Party will be on issues where the majority of Americans are pitted against a corrupt elite that dominates both parties: the national surveillance state, and its cousin, endless war. And it is here – as in the congressional opposition to the Syria bombing – that they have a positive contribution to make in the transition from the deceitful, violent, and increasingly-repressive-at-home regime of the so-called "war on terror".

It was Hillary Clinton's stubborn defense of the Iraq war that sealed her loss to Obama in 2008; and antiwar opposition also played a decisive role in the Democrats taking Congress in 2006. The 8 million-member organization Moveon.org was an important grassroots contributor to both of these changes; its members voted three to one last month to actively oppose President Obama's going to war in Syria, and they did so. They – together with lesser-known but also influential organizations of the antiwar movement – have changed the political equation for any American president contemplating war.

My own view is that 2006 and 2008 marked the end of nearly four decades of rightward drift in the United States. This includes the Clinton administration, which abandoned its campaign promises and instead delivered Nafta, "welfare reform", and the WTO. Clinton's counter-reforms were masked by the longest-running economic expansion in US history, thanks to a stock market bubble and Alan Greenspan's change of policy that allowed the growth to continue after 1996. But Clinton did as much as a Republican administration could have done to continue the record-breaking upward redistribution of wealth and income (pdf) that has transformed America into a vastly more unjust society.

In a way, Obama's election in 2008 was similar to the election of left-of-center governments that has swept across Latin America, and especially South America, over the past 15 years. Those elections were driven primarily by the failure of neoliberal (conservative) economic policies. In Latin America, the failure manifested itself in an unprecedented collapse of economic growth (pdf) for more than 20 years; in the United States, there was growth, but the gains went mostly to the richest households, and culminated in the disaster of the Great Recession. But in both parts of the western hemisphere, the voters rejected these long-term neoliberal economic failures and wanted something different.

While the Latin American voters got a lot of what they voted for, including a vastly better foreign policy, we in the United States have been less successful. But that is beginning to change.

The Occupy Wall Street movement succeeded as no pundits or politicians had in the past, in placing inequality on the media and political agenda. And now, Bill de Blasio's success in the New York mayoral race, which he is leading by a large margin, is another indicator that social justice will be a serious electoral issue in the years to come.

Obama's defeats in the last month may well turn out to be a more important part of future political changes in this country than his likely victory over the Republicans in the current confrontation.