Ordinarily, presidential candidates try to look “presidential,” and the vice presidential candidates are forced into the distasteful role of “attack dog.” This year is different, with both candidates at the top of the ticket going after each other, leaving the bottom of the ticket to be more cordial. In fact, CNN Money quotes David Axelrod, the former chief strategist to President Obama, as saying, “It may be a debate best suited for radio,” and veteran media analyst Jeff Greenfield saying, “If you could bottle the indifference with which America will treat the Pence-Kaine debate, it could put several time zones to sleep.”

Immediately following the raucous, most watched presidential debate in history, the VP debate is less likely to be outrageous.

There are several reasons for the lack of excitement, which could rival previous low-interest debates like Al Gore versus Jack Kemp in 1996. That one drew the fewest television viewers, 26.6 million, of any matchup since the first vice-presidential debate in 1976. . .

Mr. Pence and Mr. Kaine are both white men in their late 50s, with solid governing résumés, but little reputation beyond their home states. They were safe choices picked in part because they would not detract from the top of the ticket. . .

On social media, voters have compared the looming debate to watching “paint dry” and “90 minutes of Kaine and Pence quizzing each other on dad-rock trivia.”. . .

Polling before and after vice-presidential debates has shown that they do not have much effect on the overall race. A Gallup analysis before the 2012 face-off found that the median change in polling after the vice-presidential debates in 1992, 1996, 2000 and 2008 was one percentage point. . .

The 2008 debate between Ms. Palin and Mr. Biden was the most watched ever, seen by nearly 70 million viewers, more than for any of the presidential debates that year. Still, in the immediate aftermath, the Democratic ticket gained only two percentage points, and the Republicans lost one.

However, the vice presidential candidates will each have a clear mission, in an electorate which is slowly becoming less conservative.

Donald Trump’s selection of Pence of Indiana reflected a priority on unifying the GOP around cultural issues. Pence’s strongest profile is that of a conservative culture warrior.

In selecting Kaine of Virginia, Clinton has placed a priority on reaching out to swing voters. Kaine is a committed social-justice Catholic from a swing state. His electoral success has been predicated on bonding with conservative Democratic, moderate Republican and independent voters.

It’s no coincidence then that sharp shifts in public opinion underscore their selections as running mates. From 1966 until 2006, America was a center-right nation. For decades, Gallup Polls have shown there were twice as many conservatives as liberals among American voters. Roughly 40 percent of voters self-described as conservatives, about 20 percent as liberals and just about 40 percent as moderates.

Over the last decade, polling reveals that the moderate bloc has held, but liberals have grown to 25 percent, while conservatives have shrunk to 35 percent. This reflects the growth of minority, millennial, secular and highly educated professional women voters.

Consolidating each party’s base remains an essential ingredient for victory. Nevertheless, after factoring in independents who lean to one party or the other, a fully flexed GOP base would get Trump to between 42 and 45 percent of the electorate. Clinton’s Democrats, if mobilized, would hold a 45 to 47 percent share, leaving each party shy of 50 percent. This year, both parties are vulnerable to losing voters to the Libertarians, while Democrats have reason to fear the Green Party repeating Ralph Nader’s role in Al Gore’s 2000 defeat.

There are other unusual aspects.

The vice presidential debate on Tuesday night promises to be unusual on several counts.

The rivals have more time in elected office than either of their presidential candidates. Donald Trump has never served in public office and Hillary Clinton served a term and a third in the Senate before being appointed secretary of state.

Since Donald Trump, 70, would be the oldest president if elected and Hillary Clinton is only 16 months younger, their running-mates may have a reasonable expectation of contending for the top job in a future election.

The current and previous vice presidents, by contrast, were older than their chief executives. . .

Some partisans even like Kaine and Pence more than they do the presidential candidates.

Perhaps the most unusual possibility is that Hillary Clinton may be in the audience. A presidential candidate has never before attended the VP debate.

According to the official itinerary posted on her website, Clinton is scheduled to attend an organizing event in Harrisburg, Pennsylvania until 5 p.m. that day, where she will, “urge Pennsylvanians to register to vote with one week remaining before the October 11 deadline.”

While there’s no word yet on whether Clinton’s absence would help or hurt Kaine, CNN reports that he and his aides have been prepping for the sparring match in Raleigh, North Carolina, with lawyer and agent Bob Barnett standing in for Gov. Mike Pence.

Of course, polls show that 40% of Americans can’t even name the Veep candidates, so Heavy.com gives you a primer on Mike Pence, with these five main topics.

1. He Voted to Repeal the Affordable Care Act
2. He Voted to Define Marriage as Between a Man and a Woman
3. He Voted Against the 2008 Wall Street Bailout
4. He Has a Mixed Record on Immigration
5. He Has Voted for Many Trade Agreements That Trump Opposes

And if you’d like to know more about Tim Kaine, here’s a link to a story on him, covering these ten points.

1) He’s been a governor, a senator and a national party chair
2) He was a Christian missionary, and speaks Spanish
3) His eyebrow is/was a meme
4) He’s known as a nice guy’s nice guy
5) He hasn’t always been a Hillary backer
6) He was said to be favored by Bill Clinton
7) He married into a political family
8) He is a Catholic — and personally pro-life
9) He’s musical
10) He’s no Bernie Sanders or Elizabeth Warren

Related: Watch the VP Debate Live Tonight