Perhaps thinking about that campaign from the other side is important. Bush Sr. was DOWN by 17 points at about this time of year and came back from that deficit to win decisively. I think he ended up with close to 60% of the popular vote and around 400 electoral college votes. So look at that campaign and see what you can do right to overcome the current deficit instead of focusing on the single shortcoming of your candidate.

A good point. So here's what Bush's team did in 1988:

The campaign’s research showed that Mr. Dukakis’s record was not well known and that some of his liberal positions, in particular supporting prison furloughs and opposing the death penalty, could swamp him in a general election.

Using the plan laid out in that room, the Bush campaign proceeded, as Lee Atwater, the campaign manager, put it, “to strip the bark off the little bastard,” beginning in force with Mr. Bush’s hammer of a speech at the Republican National Convention in August through Election Day.
Mr. Bush not only overcame Mr. Dukakis’s summer polling advantage, but defeated him handily: by 53 percent to 46 percent. He won 40 states.

In many ways, with Mr. Atwater as its dark prince of strategy, the Bush campaign of 1988 marked the birth of the modern-day negative campaign. Most memorably, Republicans plastered Mr. Dukakis, then the governor of Massachusetts, with the case of Willie Horton, an African-American man who raped a white Maryland woman and stabbed her boyfriend while on a Massachusetts prison furlough program.

https://archive.ph/NUBAb#selection-839.212-881.50

But, of course, that strategy almost certainly isn't available to Biden's campaign. Trump almost certainly doesn't have any more "unknowns" that can be newly-introduced to voters to change their perception of the candidate. There's no "Willie Horton" in his record that voters don't already know about, so there's nothing for Biden's campaign research to uncover that can result in a game-changing negative campaign. Oh, and Biden doesn't have a time machine to go back to an era where voters were less polarized and more willing to switch parties based on new information about a candidate.

If anything, Biden's the Dukakis of the 1988 election right now - at least, more than Trump is. A significant piece of negative information has newly come to prominence in the summer of the campaign....about Biden. Which opens the door to a torrent of potential negative advertising and a new theme in the stump speech that can change public perception....against Biden.