With Bernie Sanders’ withdrawal from the presidential race, Joe Biden has no foreseeable obstacles to the Democratic nomination. That path has cleared, but the one to 1600 Pennsylvania Avenue remains murky.

Biden still has to convince Sanders’ contingent of young voters that he isn’t a corporate shill in the pocket of billionaires. He must assure the LGBTQ+ community that he’s not the same man who voted for DOMA. And he must combat a president who is actively driving a wedge between moderate and left-wing Democrats.

It won’t be easy for Joe, but he can start by making a colossally important decision.

One of the most powerful tools a presidential candidate has to boost their support in weak areas is their vice-president selection. In 2016, Donald Trump chose Indiana Governor Mike Pence as a running mate to help boost his support among Christian supporters. With stakes as high as they are in 2020, Joe Biden must decide whether he will select a running mate to garner support from the independent voting base that elected Trump in 2016 or try to rally the Bernie supporters on the left side of the political spectrum.

The one thing that we do know about Biden’s veep is that they will be a woman. Knowing this, Vox published a comprehensive list of potential running mates filled with Democratic governors, senators, and former presidential hopefuls. Among voters, the potential veeps generating the loudest buzz are Elizabeth Warren and Kamala Harris, both of whom I believe would be poor choices.

While it might appear that Elizabeth Warren would help Biden gather support among the democratic-socialist voters, nominating her as vice-president runs the risk of fury from Sanders’ supporters, who see Biden as the party favorite and Warren as the woman who stole vital votes from their candidate. Furthermore, her decidedly left-wing platform might scare off moderate voters.

If Sanders had won the nomination, Kamala Harris would be a smart choice for running mate. However, for Biden the presumptive boost in minority votes from adding Harris to the ticket seems like a waste of a veep nomination, as Biden already polls well with minority voters. Furthermore, Harris’s record on marijuana might make her toxic among young voters. Harris’ support among LGBT voters may be useful, but Biden has a much better option.

Enter Wisconsin Senator Tammy Baldwin.

Baldwin’s solidly left-wing platform would rally Sanders and Warren supporters. But she’s also from the midwest, where Biden struggled against other moderates such as Pete Buttigieg in the early primaries. Baldwin is also the first openly gay senator in American history. Her unique appeal across various contingents of the Democratic party would surely help Biden in a close race. 

Another benefit to Baldwin is her birthday. A serious concern for both Biden and Trump in the 2020 election is their age. Trump would leave his second term at nearly 80, and if Biden were to serve two terms, he would end his presidency just two years shy of titling his memoir Four Score and Seven Years Ago. At 58 years of age, Baldwin offers Biden yet another advantage.

It’s common knowledge that choosing a veep is one of the most important decisions for a presidential hopeful — but for Biden, it’s truer than for most. With sexual assault scandals preventing him from taking the moral high ground over Trump and his lack of campaign donation purity that candidates such as Sanders and Yang took such pride in, Biden must assure blue voters that he is genuinely progressive. He must also convince moderates that he can reach across the aisle, that he won’t take away their guns, and that he won’t tax them into bankruptcy. No perfect VP exists for any candidate, but for Biden a steep climb lies ahead and Tammy Baldwin is best positioned to help him carry the load.