US presidential candidates Barack Obama and Mitt Romney face off Wednesday night in the first of a series of three debates. With only five weeks to go until the 6 November elections, the pressure is on for both candidates to perform.

In polls, Obama is currently in the lead among likely voters. And the first debate will focus largely on bread and butter domestic policy issues – like the economy – that most Americans are concerned about and that could swing the most votes. We can expect heated exchanges over unemployment, the role of government, and whether or not healthcare is a basic human right.

What's not on the agenda, but should be? The record amounts of money pouring into both campaign coffers. In fact, this election cycle is on track to be the most expensive in US history. So here's a question moderator Jim Lehrer should consider asking tonight: Is $6bn in campaign spending from corporations and special interest groups good for democracy – and if we can agree that it isn't, what do we want the next president-elect to do about it?

What are they going to debate?

The lion's share of Wednesday night's domestic policy debate will focus on the still stagnant US economy. For the Romney team, who are weak on foreign policy, the 90-minute debate is an opportunity to look likeable and close in on Obama's lead using high unemployment figures and low national economic confidence. (Romney will probably try to avoid questions about his now infamous 47% speech, where he lambasted nearly half of Americans for their "dependence" on government.)

The crux of the economic debate is fairly predictable. Romney will call for lower taxes on job creators (a flattering and deceitful euphemism for the rich) and some difficult "belt tightening" when it comes to social welfare programs, which tend to help the poor. This is, more or less, the new world equivalent of much of Europe's disastrous austerity regime. Obama will likely counter with his austerity light programme: limited stimulus, cuts in spending and proposals for temperate reform to social welfare programs like Medicare.

Another big, and ironic, point of contention, will be healthcare. Obama passed the the largest and most comprehensive healthcare reform law ever, which aims to provide private sector care to all Americans. Romney, who has promised to "repeal and replace" the Affordable Care Act, is likely to call the reform another example of big, intrusive government – even though the plan is modeled on a bill he championed as governor of Massachusetts.

May the best (or richest?) man win

What are we not likely to hear about tonight? The official debate topics have already attracted a barrage of criticism from activists who believe that issues like gun control, immigration and climate change should be on the agenda. And a crucial issue that thousands have called to be discussed is the massive amounts of cash being spent on both sides by a small group of billionaires and corporations to influence and manipulate voters. This issue goes to the heart of how US democracy is being corrupted and who has influence over the winning candidates' policies that not only affect Americans, but impact on us all.

This influx of money into politics has become so extortionate in large part because of the US supreme court's 2010 ruling on Citizens United, which found that the government cannot restrict political spending by corporations, labour unions and other organisations in elections. The decision in effect gave corporations the same free speech rights as people, giving rise to vast spending – and a mad scramble for cash on both sides of the political aisle. Staggeringly large amounts of money have been given and raised by a tiny group of people, while the vast majority of Americans are left wondering what those donations are buying, and many are concerned that their elections have become auctions.

As a result, calls are mounting for a constitutional amendment to overturn the Citizens United decision and reinstate reasonable limits on campaign spending. Many believe such an amendment is the only long-term solution to this billion-dollar assault on US democracy. But where do the candidates actually stand on the issue?

One of these things is not like the other

Obama has made his views relatively clear (current campaign spending aside). In an online Q&A via Reddit, the very first question posed to Obama was: "What are you going to do to end the corrupting influence of money in politics during your second term?" His response: "Over the longer term, I think we need to seriously consider mobilising a constitutional amendment process to overturn Citizens United (assuming the supreme court doesn't revisit it)".

Romney, on the other hand, has yet to take an official position on a constitutional amendment. He did, however, praise the supreme court’s decision in Citizens United, stating: "I think their decision was a correct decision. I support their decision. I wish we could find a way to get money out of politics. I haven’t found a way to do that." Romney has also proposed allowing unlimited donations directly to candidates, instead of the current system of unlimited contributions to special political action committees.

One thing is clear: voters on both sides of the aisle are sick of the flood of cash flowing straight from the wealthy into America's electoral system – polluting US politics and undermining democracy. Let the debate begin!

Sources: Washington Post, Politico, Huffington Post, Avaaz, CNN, New York Times, Reuters, Christian Science Monitor, Reddit, International Business Times, Elections not Auctions