The vice-presidential debate on Thursday will inevitably lead to media commentary arguing it is of no consequence that one of the candidates lost the debate (or has been deemed by polls to have lost). After all, they will argue, voters vote for a president and not their running mate. Their running mates are simply campaign surrogates and attack dogs that have no bearing on a person’s vote.

But they are wrong. Or at least they should be. The vice president matters — now more than ever.

The vice president is more than an advisor in the White House. When watching the debate on Thursday, voters should be asking themselves: “Am I comfortable with this person taking over as President?” 

Many think the chances are low that the vice president will have to assume power. However, eight presidents have died while in office — from William Henry Harrison to John F. Kennedy (that’s over 18% of the presidents in our young nation’s history). Meaning eight times a vice president has taken over as President.

But power has temporarily shifted to the vice president many more times. Whenever a president needs anesthesia, even for a brief routine procedure, the vice president assumes the power of the presidency. The same would be true if a president fell ill or was in a coma or an unconscious state for a period of time.

If President Obama needs a colonoscopy, do you feel comfortable with Acting President Biden? 

What if an attack on the United States happens during those few hours? That would be some coincidence, wouldn’t it? 

Maybe it wouldn’t be a coincidence at all. This day in age, terrorists have intelligence just like we do. Not that they need it. President Bush’s routine medical procedure to remove polyps was publicized well ahead of time in July 2007, and the entire world knew Vice President Cheney was taking the reins. If a terrorist group sees a transition of power as a moment of weakness, they will have all the information they need to stage an attack and take advantage of that weakness.

The national security threats of today not only create a challenge should a vice president take over, they increase the chance of such a transition. Terrorists have flown a plane into the Pentagon — our center of national defense. They have taken down two enormous office buildings. Is it unimaginable they will attack the White House? Air Force One? The president himself?

We live in a daunting age with many external threats. We know about some of them, but only the president knows about many more. The debate on Thursday will span every issue, domestic and foreign. I hope voters listen carefully and evaluate each candidate as a president, a title one of them is or will be only a heartbeat from holding — whether for minutes or years.