Their second debate is not until Sunday, but Mr Donald Trump and Mrs Hillary Clinton still loomed large when their running mates engaged in an often testy verbal duel focused predominantly on who had the worse boss.
In the only vice-presidential debate of the campaign on Tuesday night, Democrat Tim Kaine and Republican Mike Pence spent more time attacking the candidates at the top of the ticket than actually taking each other on.
They often interrupted each other, spoke over one another and embarked on unrelated tangents - forcing the moderator to urge them to let the other speak and also to remind them of the question asked.
The result was a 90-minute brawl that experts said was unlikely to sway undecided voters but could inject some energy into the bases of the two camps.
"Trump has faced numerous challenges this week and because Trump - and his weaknesses - played such a dominant role tonight, that narrative will not change. It does not put the GOP (an acronym used by the Republican Party) ticket in a worse place, but tonight's debate will do little to change the conversation," wrote Brookings Institution senior fellow John Hudak.
Mr Pence had arguably the more difficult job heading into the debate.
After Mr Trump's poor performance at the first presidential debate, the campaign had been besieged by problems ranging from an ill-advised Twitter attack on a former beauty queen to reports that the billionaire might have avoided paying income tax for nearly two decades.
The Indiana governor put in a calm, polished performance but notably steered clear of trying to defend Mr Trump's most controversial statements. Sometimes, he simply denied the billionaire had said them.
He also sought to turn the tables on the Democratic Party ticket by accusing it of being more "insult-driven" than his own.
"If Donald Trump had said all of the things that you've said he said in the way you said he said them, he still wouldn't have a fraction of the insults that Hillary Clinton levelled when she said that half of our supporters were a basket of deplorables," he said, in a bid to make up for Mr Trump's earlier failure to take Mrs Clinton to task for her remarks.
He also revised some of Mr Trump's positions to ones closer to the Republican orthodoxy, softening the tycoon's position on deporting illegal immigrants and also promising to be tough on Russia.
An indicator of his performance was an instant poll of debate watchers conducted by CNN/ORC, giving him a narrow win over Mr Kaine.
If Mr Pence succeeded in attacking Mrs Clinton while skirting around Mr Trump's flaws, Mr Kaine also succeeded in ensuring the tycoon's remarks got an airing.
The Virginia senator repeated Mr Trump's controversies ad nauseum, shoehorning mentions of his failure to release tax returns and the dealings of the Trump Foundation into discussions about Russia and North Korea.
He also kept pushing Mr Pence to defend his running mate.
"Six times tonight I have said to Governor Pence, I can't imagine how you can defend your running mate's position on one issue after the next. And in all six cases, he's refused to defend his running mate."
The most substantive exchange of the night came in one of those rare moments when the two candidates were not trying to prosecute a case against the presidential nominees.
Asked about the tension between faith and public service, the duo engaged in a debate about abortion that highlighted a clear division in their parties' approach to the issue.
Both men spoke passionately about their faith but drew different conclusions about what that meant for policy.
Mr Pence said: "My faith informs my life. For me, it all begins with cherishing the dignity, the worth, the value of all human life."
Mr Kaine, in turn, responded: "I think you should live your moral values, but the last thing governments should do is to have laws that would punish women who make reproductive choices."
With the end of the vice-presidential debate at Longwood University in Farmville, Virginia, the spotlight returns to the two main candidates, who will face off in the second of three debates on Sunday.
Both were quick to praise their respective running mates.
"Lucky to have a partner like Tim Kaine who stood up for our shared vision tonight - instead of trying to deny it," Mrs Clinton tweeted.
Mr Trump wrote: "Mike Pence won big. We should all be proud of Mike!"