It happens every four years: Pundits begin to talk about how absolutely pivotal the presidential and vice presidential debates will be.

At the same time, they conveniently ignore the reality that, apart from President Ford insisting that there was no Soviet domination of Eastern Europe in his second debate against Jimmy Carter in 1976, and the famous 1960 debate between John Kennedy and Richard Nixon, debates have almost never affected the outcome of a presidential election. In fact, undecided voters rarely watch debates, as viewership is limited mostly to the partisans on each side, who hope their team will score and the other will choke.

Something else happens right about now every four years: Pundits start to shout that it “all comes down to turnout.” Here, they have a point. This year, in fact, we may well see the highest voter turnout in American history, matching the 65 percent of the voting-age population that cast their ballots in 1940 and 1960. (Keep in mind that noncitizens and felons in states that do not allow them to vote are included in the number.)

Both party bases have been extremely motivated, even before Justice Ruth Bader Ginsburg passed away, which is why the Supreme Court battle's impact on the presidential race will be very limited. In the Senate, however, the increased partisan reaction to Trump’s nomination might make it harder for Democrats in certain red states to convince enough Trump voters to cross over and vote for a Senate Democrat. Conversely, for Republican Senate candidates in states that Trump is likely to lose, they will need some Biden voters to swing their way.

With the U.S. getting better educated and more ethnically diverse all the time, coupled with Trump’s aversion to expanding his appeal beyond his 40-to-42-percent base, many see his only path as boosting the share of white voters without college degrees. David Wasserman, The Cook Political Report’s House editor and resident quant, observes that “if the race/education breakdown of the 2016 election were applied to 2020's demographic realities, Biden would gain roughly 1.8 points on Clinton's national popular-vote margin (2.1 to 3.9).”

To demonstrate how shifts in the makeup of the electorate and their preferences can change the outcome of the election, Wasserman recently helped put together an American variation on the BBC’s famous “Swingometer,” a display of election data unlike anything any U.S. network has ever done.

Wasserman’s version, explained in this Cook Political Report article, allows people to test how shifts in vote preference from 2016 to 2020 by certain demographics will affect the outcome in the Electoral College. It’s a good way to kill an afternoon, particularly if you are home without a boss looking over your shoulder.

Unless Trump pulls a rabbit out of a hat, or Biden completely chokes in the first debate Tuesday night, this race will remain in something considerably less than a competitive situation. Polling, particularly the higher-quality polling on both the national and state levels, paints a bleak picture for the president.

My thoughts are increasingly moving toward whether the GOP can hold onto their majority in the Senate. If the Republicans are extremely lucky, they can keep their losses down to just one or two seats, holding onto their majority by the skin of their teeth. On a really bad Election Night, Republicans could lose five, six, or even seven. Keep in mind they’re defending nine competitive seats, while Democrats are only concerned with two (Alabama and Michigan).

Given how many relatively small states are very close—Maine, Montana, Iowa, Kansas, and South Carolina—we could easily see the difference between a really good night for Republicans and a crushing defeat come down to a matter of 50,000 or 100,000 votes.

With the increasingly partisan nature of our politics today and less ticket-splitting than ever before, it’s important to keep in mind that one party usually wins the lion’s share of the really close contests. Years ago, our very talented then-Cook Political Report Senate Editor Jennifer Duffy observed this and put together a handy chart that we have kept updated. For instance, in 1998, Democrats won six out of the seven Senate races rated as Toss-Ups going into Election Day in The Cook Political Report. In 2000, Democrats prevailed in seven out of nine; in 2002 the GOP won six out of nine. In the most recent elections, Republicans won eight out of nine in 2014, five out of seven in 2016, and five out of nine in 2018, the most even split over the 11 elections covered.

The possibility of an explosive Senate result is very real, and dependent upon relatively few votes. And given how badly the congressional and presidential races are going for the GOP, the Senate may end up being the big casino on Election Night.

This story was originally published on on September 30, 2020

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