Conventional wisdom says that tonight’s first presidential debate of 2020 won’t move the needle. It also says that Donald Trump made a mistake by setting low expectations for Joe Biden’s mental acuity.

            As usual, conventional wisdom is wrong.

            95% of American voters have never heard Joe Biden speak for more than five minutes. They didn’t watch the Democratic primary debates. Obama didn’t give Biden many high-profile speaking opportunities as vice president. The last time Biden was on the national stage was during the Clarence Thomas confirmation hearings — 28 years ago. You have to be over 50 years old to remember them and even then, he didn’t say or do anything worth remembering as chairman of the Senate judiciary committee. For all practical purposes, only one of these two men has actually been running a semblance of a campaign this year. Biden has not. All that people know is that Biden was Obama’s vice president and that he’s been in DC a long time.

            Biden’s support is almost entirely a negative reaction to President Trump. No one is talking about Biden’s affirmative agenda, such as it is. People aren’t voting for Biden, they are voting against Donald Trump. Therefore, tonight is about Joe Biden.

Tonight’s debate will therefore be Joe Biden’s first true introduction to the American people. Many of the people who have already decided to vote for Joe Biden will be disappointed when they finally focus on the election and Biden himself over the course of 90 long minutes. Some voters could feel buyer’s remorse. That could certainly feed the enthusiasm gap that already favors Trump.

For Donald Trump, nothing much is at stake. His support is baked in. Everyone knows the president and has formed their opinion. Nothing he says, no matter how outrageous, will get Trump into serious trouble. His goal, or at least it ought be his goal, is to expose Joe Biden as unfit for office. He will do what Trump does best, goad and troll and poke and prod in the hope that Biden decompensates into unseemly anger or nonsensical rants.

Whether that works or not will depend on which Joe Biden shows up tonight. Will it be the ghostly half-dead victim of dementia who, during the primary debates, couldn’t wait for his 60 seconds to be over? Or will it be Biden in honey badger mode, the guy who shoves voters and calls them dog-faced pony soldiers? If it’s Sleepy Joe, the debate is over and so is this campaign. If it’s Weird Malarkey Joe, things could get interesting.

Reports from inside the campaign say that Biden intends to focus on Trump’s incompetent and counterproductive reaction to the COVID-19 pandemic. The recent New York Times stories about Trump’s finances and taxes will certainly add more grist for the mill.

If I were preparing Biden, I would advise him to come out of the gate the way Kamala Harris did against him during the primary, balls to the wall: “You killed 200,000 innocent Americans. I want you to stand up here and apologize to their friends and families.” Obviously Biden has to use the tax issue, but I wouldn’t linger on it. All Donald Trump has to do is mention Hunter Biden, Burisma, Ukraine and then it becomes a game of I know what I am but what are you?

Aside from Biden’s advanced age and the obvious mental issues that go with it, one thing Democratic voters are going to want to see is a willingness and ability to fight and be aggressive. Voters always expect the president to exude strength. Democrats, however, tend to fall short on that metric and Biden even more so than most. Biden has an opportunity to show that he knows how to attack and how to punch back. I am not optimistic on this front.

Donald Trump’s biggest disadvantage tonight is that he never prepares for debates or any public appearances. He won’t be able to cite statistics or draw upon details in any kind of credible way. But I don’t think that’s going to matter. Ultimately this is a contest of personalities and tone, and nobody’s going to care about who knows the capital of Vanuatu. If I were Trump, I would keep up the attacks on Biden’s mental state and acuity and provoke him into losing it over something personal.

Tomorrow morning Democrats are going to say that Joe Biden won and Republicans are going to say that Donald Trump won. When historians look back with some objectivity, I think they will write that Trump carried the night.