Comparing Tim Kaine and Mike Pence before the debate

Vice-presidential candidates are traditionally expected to fulfill the roles of attack dogs and loyal surrogates. While other aspects of the 2016 race have defied expectations, this tradition remains largely intact for Democrat Tim Kaine and Republican Mike Pence.

Kaine has spent his time raising millions of dollars for the Clinton campaign in glitzy fundraisers while repeatedly slamming Donald Trump’s policy positions and controversial statements.

Mike Pence has similarly kept up criticism of Hillary Clinton regarding topics such as Benghazi and her use of a private email server as secretary of state. He’s also staunchly defended Trump’s positions on issues such as immigration, and is often regarded as a moderating influence on the brash billionaire.

So far, the vice-presidential candidates have mostly stayed out of the spotlight. Although they frequently attack the opposing presidential candidate, they have rarely confronted each other directly.

That all changes on Tuesday night, when Kaine and Pence will be featured in the vice-presidential debate. The two undercards will have the chance to argue for their candidates and undermine their opponent’s records in front of millions of potential voters.

How do the vice-presidential candidates compare to each other?

Kaine is a familiar figure in Virginia politics. He served as mayor of Richmond from 1998 to 2001, before serving as lieutenant governor from 2002 to 2006. He was elected governor and served until 2010 before successfully running for the U.S. Senate in 2012.

Pence also has a long history in his home state of Indiana. Pence served as a U.S. congressman representing the Hoosier state’s Sixth Congressional District from 2001 to 2013, after which he was elected governor.

PolitiFact has looked at 39 of Kaine’s claims on the Truth-O-Meter. 77 percent of them were ranked as either True, Mostly True, or Half-True.

We’ve also looked at 26 of Pence’s statements. 58 percent were ranked as True, Mostly True, or Half-True.

Neither candidate has had any claims ranked as Pants on Fire.

Standouts from Kaine’s record

Even before the presidential election, Tim Kaine went on the record in November of 2014 to defend President Obama’s decision to bypass Congress on immigration. He said that every president since Eisenhower has taken executive action on the issue. His message was mostly correct, but Obama’s actions were far more sweeping and broader in scope than those of his predecessors. We gave it a Mostly True.

Before the Democratic convention, Kaine took to MSNBC to argue that Donald Trump wants to "privatize the Veteran’s Administration." The claim was part of a larger effort to undermine Trump’s perceived focus on improving the lives of vets nationwide. However, Trump never actually claimed that he wants to privatize the whole system. Rather, Trump wishes to provide veterans potential access to private providers. We gave Kaine’s claim a Mostly False.

In August, Kaine criticized Trump’s refusal to release his tax returns by stating that even Richard Nixon released his returns when he was running for president. However, we found that Nixon didn’t actually release his returns until a year after he was re-elected in 1972. We gave it a Mostly False.

Kaine has also defended his own record as governor and senator. He claimed that in the dark aftermath after the Virginia Tech shooting, his administration quickly acted to eliminate a loophole in gun laws to prevent mentally ill people who are potentially dangerous from obtaining a firearm. Kaine can claim credit for fixing the loophole, so we gave it a True.

Standouts from Pence’s record

Like his Democratic counterpart, Pence frequently lambasts his presidential opponent’s perceived weaknesses while giving toned-down versions of Trump’s more controversial arguments.

Back in July, Pence claimed that Hillary Clinton took thirteen hours to send help to besieged Americans during the 2012 Benghazi attack. However, the responsibility to send troops fell to the military chain of command, not Clinton. We rated the statement False.

Pence later drew a strong contrast between Trump and Clinton’s immigration policies. He received a True for correctly pointing out that Clinton wanted to expand upon Obama’s refugee resettlement program and increase the number of Syrian refugees to the U.S. by 550 percent.

In September, Pence defended Trump’s immigration stance by saying that the candidate has been completely consistent about his plans for undocumented immigrants. But the reality is that Trump has been vague and self-contradictory on the issue, so we gave Pence’s claim a False.

When not weighing in on the presidential candidates, Pence frequently touts his record as governor of Indiana. He’s claimed on multiple occasions that there are more people working in Indiana than ever before. Although he’s right about the raw numbers, the percentage of Hoosiers who are working isn’t as high as its peak in the year 2000. We gave it a Half True.

Kaine and Pence may rehash these arguments during the debate, but they may also make new claims and criticisms of both the presidential candidates and each other. As always, we’ll be there to check the facts.