Oh, there'll be an audience -- maybe 60 million people, pretty big viewership compared to a normal TV show. But the audience won't hold a candle to past presidential debates.
Consider this: Of the ten most-watched presidential debates in history, none took place in the 21st century.
George W. Bush's first 2004 clash with John Kerry did OK, drawing 62 million viewers, but Bush-Al Gore in 2000 and Obama-John McCain in 2008 were relative duds. In 2008, in fact, the Sarah Palin-Joe Biden vice presidential debate drew far more viewers than Obama and McCain.
Some Republicans hope tonight's discussion will reverse those trends and reset the race. They point to the most-watched debate ever, the 1980 exchange between Ronald Reagan and Jimmy Carter, as the template for a landslide victory over an incumbent.
Maybe. Tonight's exchange is a good opportunity for Romney, who trails in the polls.
But it's highly unlikely Romney-Obama will match Reagan-Carter in audience or impact, mostly because the media environment has changed so dramatically since the Gipper faced the peanut farmer.
In 1980, millions of Americans had never heard Reagan speak. CNN was less than six months old. Other cable networks didn't exist. Talk radio wasn't a factor. The Internet was a gleam in Steve Jobs' eye. Most Americans read newspapers or news magazines.
Today, we're drowning in a multi-media deluge of news and opinion that is almost always aimed at a narrow, already-convinced audience. Obama supporters aren't watching Fox News and Romney fans aren't watching MSNBC.
When you think about it, is there anyone left in 2012 who hasn't heard or seen Mitt Romney or Barack Obama? Is there anyone who plans to vote who hasn't seen or heard enough to pick a candidate?
That's why viewership for the debates is tanking. And that's why they may not matter as much as they did in 1980.
Some Republicans, watching Romney slip in the polls, have started their quadrennial chorus of mainstream media-bashing. Political reporters, we're told, are in the tank for the Democrat, an argument they've made for decades.
Even if that were true -- which it isn't -- Republicans today have an alternative: blogs, cable shows, opinion websites, talk radio, the whole wide media landscape. So do Democrats.
But those outlets are better at reinforcing opinions than making them, an equation unlikely to change tonight.
So consider this irony: The 1980 Reagan surge was prompted by a classic mainstream media event, a mass-audience, 80-million-viewer debate.
Those hoping for a similar bounce for either side after tonight will likely be disappointed.