A 'heartbeat away' from the Oval Office: How Tim Kaine and Mike Pence stack up ahead of debate

Nobody really votes for them. Few would consider them household names in U.S. politics.

And yet, come November, one of the vice-presidential running mates — a Spanish-speaking senator from Virginia or a Indiana governor perhaps best known outside Indiana for supporting the Hoosier state's controversial "religious freedom" bill — will inherit the most powerful subordinate office in the United States.

If past vice-presidential debates are any measure, chances are slim that Tuesday night's faceoff between Democrat Tim Kaine, a senator from Virginia, and Republican Mike Pence, a governor of Indiana, will needle the polls in a major way.

• Keith Boag: The 'change' candidate can't change his ways in 1st debate
• ANALYSIS | #TrumpWon the debate? Legitimate polls show otherwise
• Presidential Poll Tracker: Check out the latest projections

But the contest of the running mates gives the electorate an extended look at how the next person to be "one heartbeat away" from assuming the Oval Office might govern, says Joel Goldstein, a scholar on the vice-presidency who lectures at Saint Louis University School of Law.

"The main mark or target isn't these two guys, it's the top of the ticket," Goldstein says. "But another function of the V-P debate is to let the American people meet the First Successor, and to see how they could be plausible presidents."

Who is Tim Kaine?

"Boring" by his own admission, Hillary Clinton's running mate was considered a safe choice among progressive liberals, boasting a 100 per cent voting record with Planned Parenthood, though he personally opposes abortion. He scored a 90 per cent congressional voting record from Americans for Democratic Action in 2014.

Kaine is one of 20 people in U.S. politics to have reached a rare trifecta of governance, as a former mayor of the City of Richmond, a governor of Virginia and a popular senator from that state.

At 58, Kaine is a decade younger than Clinton. She has pitched him as a person that she not only gets along with, but who would also be qualified to take over the Oval Office were she to win the election but somehow become sidelined.

Kaine is a devout Catholic who has long attended a predominantly black church. While studying at Harvard Law School, he took a year off to perform missionary work in Honduras, where he learned Spanish. His fluency in Spanish could help with reaching out to a vital Hispanic electorate and his popularity in Virginia could help the Democrats carry the swing state.

Kaine was high on the short list to be Barack Obama's running mate in the 2008 presidential campaign, although Obama ultimately chose Joe Biden.

He also plays harmonica in a bluegrass band. Apparently quite well.

Who is Mike Pence?

Next to his presidential running mate Donald Trump, Pence, 57, certainly represents the quieter side of the ticket, although he made a lot of noise internationally last year. That's when as governor of Indiana, he signed a controversial Religious Freedom Restoration Act that allowed businesses and individuals to refuse service to LGBT people on faith grounds.

The bill, decried as discriminatory, caused a furor that reportedly cost Indianapolis up to $60 million in lost revenues, according to the Indianapolis Star. (Pence eventually signed an amendment to prohibit discrimination against gay people.)

The evangelical Christian was also a former congressman and before that, a radio talk show host who described himself as "Rush Limbaugh on decaf." 

Pence has an A-plus rating from the NRA. His conservative credentials and popularity among Republicans makes him a safe choice for the party, while his political experience should complement Trump's outsider candidacy.

In the Indiana primary, Pence endorsed Ted Cruz, although he also voiced tacit support for Trump.

Pence told The Hill in 2009 that his favourite hobby is horseback riding.

How Kaine splits from Clinton

Kaine said as late as July that he maintains moral support for the Hyde Amendment, which bars federal taxpayer-funded abortions, even though Clinton's policy agenda includes repealing Hyde.

His statement drew criticism from pro-choice groups, though Planned Parenthood said that "while we strongly disagree with Senator Kaine on this point, there are many places where we do agree."

How Pence splits from Trump

In a break with Trump, Pence said "there's no question" that human activity has an effect on climate change. Trump has previously tweeted that global warming was "created by and for the Chinese," but denied on the debate stage last Monday night that he ever said it was a hoax.

In August, Pence and Trump diverged over their endorsement of House Speaker Paul Ryan in his Republican primary. While Trump declined to endorse Ryan, Pence, a longtime friend, said he had Trump's blessing to go ahead with his endorsement.

What to watch for Tuesday night

Don't expect fireworks, says Goldstein, the vice-presidential expert.

Both public servants have pretty sedate personalities, and although they will be "introducing themselves" to America, he says, the debates will likely focus on hyping their presidential running mates.

A blemish on Kaine's record is his own disclosure that he accepted more than $160,000 in clothes and vacations as gifts, all of which were at the time legal under Virginia's ethics rules, while he served as lieutenant-governor and governor.

Kaine's defenders note that there was no whiff of quid pro quo associated with the gifts, but it provides potential fodder for attacks, Goldstein says.

"The debates will be about suggesting that Trump is hostile to women or gays because Pence was involved in trying to defund Planned Parenthood, or signed a religious law in Indiana," he says.

• 'I did not say that': A look at who lied about what in the U.S. presidential debate
• How a president is elected

The Republicans will be trying to attack the Democrats as corrupt because Kaine accepted gifts, "which ties in with their narrative about Secretary Clinton," Goldstein says.

"I think Kaine is going to make Pence defend a lot of ground based on Trump's statements and conduct, and I think that Pence is going to try to attack Clinton on trade," he says, adding that Kaine may be in a "no-lose position."

Kaine will be free to remind voters of disparaging remarks Trump has made while hanging them on Pence for comment, and putting him in the "awkward position" of either defending the remarks or distancing himself from his own running mate.

Debate prep and details

Kaine has been privately preparing against a Pence stand-in played by Washington lawyer Bob Barnett. Pence has been sparring against Scott Walker, the republican governor of Wisconsin who has been portraying Kaine.

The debate, to be moderated by CBS News anchor Elaine Quijano, takes place at 9 p.m. ET on Oct. 4 at Longwood University in Farmville, Va. It will run for 90 commercial-free minutes and will be broadcast on all major TV networks and cable channels.

There will be nine segments lasting 10 minutes each. The debate will begin by the moderator asking an opening question, after which each candidate will have two minutes to respond.