When the vice-presidential nominees debate Tuesday, they’ll be asked to explain their stances on issues where they disagree with each other — and with running mates Donald Trump and Hillary Clinton. A look at where Democratic Sen. Tim Kaine and Indiana Gov. Mike Pence, a Republican, stand on the key policy disputes:

On abortion

Kaine: A Catholic who personally opposes abortion, as governor he backed some limits on abortion. In 2005, he said he had a “faith-based” opposition to abortion. He has voted in favor of policies supporting a woman’s right to choose since coming to the Senate in 2012.

Pence: In 2011, he said that he longed “for the day that Roe vs. Wade is sent to the ash heap of history, when we move past the broken hearts and broken minds of the past 38 years.” He voted for the criminalization of abortion services during his tenure in Congress.

On the environment

Kaine: He voted to curb carbon pollution and against the Keystone XL pipeline. He opposed an amendment that would have closed a loophole exempting fracking water from being regulated under the Safe Drinking Water Act. He backs offshore drilling in the Atlantic.

Pence: He has denied the existence of climate change and voted to eliminate funding for climate-change education programs and to bar the Environmental Protection Agency from regulating greenhouse gas emissions. He supports fossil fuel development and offshore drilling.

On foreign policy

Kaine: He has endorsed U.S. intervention in Syria and Libya and voted in favor of the Iraq war. He backed the Iran nuclear deal and supported the normalization of U.S. relations with Cuba.

Pence: He voted for the Iraq war and co-sponsored the resolution. In 2008, he sponsored a measure to increase sanctions on Syria. In 2011, he voted to bar sending U.S. troops to Libya without congressional approval.

On gun control

Kaine: He has said that he’s a gun owner but supports “common-sense legislation” including background checks and restrictions on sales of assault weapons. He supported a bill that would expand background checks to gun shows and internet sales, and supports a ban on gun sales to people on the terror watch list.

Pence: In 2005, he supported a bill to protect gun manufacturers from lawsuits from victims of gun violence. In 2010, he co-sponsored a resolution to commend the National Rifle Association for a program that teaches children gun safety. The NRA has given him an “A” rating and financially supported his campaigns.

On gay rights

Kaine: In 2006, he campaigned against a Virginia constitutional amendment that would have banned same-sex marriage, and in 2013 said that he supported gay marriage

Pence: In Indiana, he fought for legislation that would have allowed businesses to deny service to people based on religious beliefs, a measure seen as an avenue to same-sex discrimination.

On immigration

Kaine: He supports the same immigration protections that President Obama has long advocated, including the option of full citizenship for illegal immigrants if they pay taxes and a fine.

Pence: He opposed the resettlement of Syrian refugees in Indiana, but called Donald Trump’s plan to bar Muslims from entering the U.S. “offensive and unconstitutional.” In 2009, he voted for a Mexican border fence.