Bradley Tusk is CEO of his own firm, Tusk Ventures, which consults with companies that work with government. He was campaign manager for Michael Bloomberg's successful re-election bid as New York City mayor in 2009 and served as deputy governor of Illinois from 2003 to 2006. The opinions expressed in this commentary are his.

(CNN) Despite what many of us want to believe, President Donald Trump is the front-runner in 2020. If you supported him in 2016, you have little reason to regret your choice -- he's working hard to fulfill all his campaign promises. Sure, the polls often show that Trump's approval rating is underwater. But voters are a lot more than just data points graphed onto projections.

No incumbent president in recent history has presided over a strong economy, not been enmeshed in a ground war and lost the next election. So, for those of us who desperately want to see a new president, just telling ourselves that a majority of the voters in key states will see what we see and feel how we feel isn't enough to actually win. It's going to take more than the constant tearing of garments and endless howls of outrage to beat him. It's going to take an outside factor -- like Justice Anthony Kennedy's retirement.

Bradley Tusk

There's no easily foreseeable reason the Senate won't be able to confirm whomever Trump nominates. In theory, Sens. Susan Collins, R-Maine, and Lisa Murkowski, R-Alaska, could join the 49 Democrats and slow the process, but it may not be realistic to expect every Democrat to stick together, particularly ones up for re-election in red states.

That means the next Supreme Court justice will likely view Roe v. Wade as bad law and eventually vote to overturn it. If the Republicans are smart, they'll do everything in their power to persuade the court to wait until after the 2020 election, since according to the latest Pew poll, a majority of Americans support abortion in all or most cases.

But let's say the five conservative justices can't restrain themselves, accept a case that challenges the underpinnings of Roe, and then overturn 45 years of precedent giving women the right to choose. From a moral standpoint, it's hard to imagine a worse outcome. But from a political standpoint, it may be the only way to beat Trump.

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