The debate in Virginia will thrust Sen. Tim Kaine of Virginia and Indiana Gov. Mike Pence into a national spotlight recently hogged by Clinton and Trump, respectively. The vice presidential candidates will likely aim to take down each other's records and try to prop up their unpopular running mates.
The event comes as recent polling suggests Clinton has re-established her grip on a race that appeared neck and neck just more than a week ago. Clinton's average lead over Trump in recent four-way national polls, which include the Libertarian Party's Gary Johnson and the Green Party's Jill Stein has grown to 3.7 points, up from only 1.6 points on Sept. 26, the day of the first presidential debate, according to Real Clear Politics.
After the debate, which most voters in scientific polls said Clinton fared better in than Trump, swing-state polls also showed a shift in the Democrat's favor. Recent polling averages show her with an edge in Pennsylvania, Colorado, Florida, North Carolina and Virginia, while Trump leads in Arizona, Iowa and Ohio.
Kaine, a former Virginia governor known as a more moderate Democrat, will likely defend Clinton's trustworthiness and record during the debate. The Republican National Committee also telegraphed another point of attack against him in a recent ad criticizing Kaine for defending convicted murderers as an attorney.
Pence, who could have a large policy role in an administration headed by a man who has never held public office, will try to portray policy cohesion for a campaign that has often lacked consistency. He will also likely defend his staunchly conservative record on abortion and gay marriage.
The next presidential debate is set for Sunday in St. Louis.