Joe Biden's grip on front-runner status seemed to be slipping away after getting mauled by Sen. Kamala Harris in the first Democratic debate. But after the initial effects wore off, Biden slowly rebuilt his lead and is now he heads into the second debate in the same position as he was before the first one.

Specifically, on June 27, the date of the first Democratic debate, Biden was at 32% in the average of polls compiled by RealClearPolitics, and Harris was at 7%. By July 5, Biden's support had fallen to 26% as Harris soared to 15.2% — cutting his lead to the single digits. But as of this writing, Biden is right back at 32% while Harris has lost most of her gains, and is now at 10.5%, or back to over 20 points behind.

There are many ways to look at this turnaround. Biden has proven himself resilient after several rounds of negative media attention. Biden does not have much competition in the field from traditional liberals, whereas his opponents are carving up the far-left component of the electorate. Additionally, Democrats have a generally favorable view of Biden that doesn't always come across to those who are following the election mainly through social media.

All of this having been said, even if the first debate did not permanently wound Biden, it did suggest that he's extremely vulnerable to attack and slow on his feet, and if that continues as people pay more attention, his standing could rapidly change.

So, Wednesday's debate will be extremely important for Biden, because a strong performance could reassure supporters, while a shaky one could start to establish a pattern of him being not up to the task of running for president, and such a pattern will in fact be devastating.