The natural response to the disaster that is President Donald Trump is to dream of a better future. Wouldn't it be nice not to worry about the president imperiling national security with his ill-advised tweets or wonder whether his campaign colluded with a foreign government to win the election? Wouldn't you rather the debate over healthcare not be about millions of Americans potentially losing insurance?

So it's not particularly strange, less than a year into Trump's first (and hopefully only) term, that people are already speculating who the Democratic 2020 nominee will be. And what's become obvious is that the Democratic front runner is the man many people are saying would have beaten Trump, Vermont Senator Bernie Sanders.

On Wednesday, when asked about a 2020 run on Sirius XM, Sanders said, "I am not taking it off the table. I just have not made any decisions. And I think it's much too early." That's an answer designed to keep speculation, and hope, about his run alive. As Sanders travels the country campaigning for other Democrats and promoting his new book in the key primary state of Iowa, it seems as if another presidential run is affirmatively on the table.

Despite his age—he will 79 by the next inauguration day, so if he were to win he'd be the oldest president to ever assume office—Sanders is the best 2020 presidential candidate the Democrats have. According to a Harvard poll from April, he is the most popular politician in the country, with 80 percent of Democrats and 57 percent of registered voters viewing him favorably. A recent Morning Consult poll that ranked senators by how popular they were with their constituents had Sanders in the number one spot.

In an essay arguing against a Sanders 2020 run, The New Republic's Sarah Jones argued that "name recognition is key to victory, but it can also strangle movements. Sanders the individual now gobbles up so much airtime and column inches that he threatens to eclipse the American left, to its long-term detriment." But while Bernie Bro madness might take away focus from building a larger leftist movement, which is surely vital for 2020 success, having a cult of personality didn't hurt the last two men who won national elections.

Even though Sanders has been in some sort of elected office since 1981, he's still understood as an outsider, an increasingly appealing persona in an era of intense anti-establishment rage. His official status as an independent, not a Democrat, enrages some in the party but his repeated criticism of Democrats is essential to his personal brand. It also sparks enthusiasm among disgruntled lefties feeling forgotten by their party. The success of his 2016 run—where he championed pocketbook ideas like single-payer healthcare and higher minimum wage—has been vital to pushing the Democratic Party left. He's done more than anyone to combat the right-wing message that government-funded social services are oppressive or antithetical to freedom.

While there's a small but ferocious group of anti-Sanders Democrats still bitter about his 2016 run, which they believe critically damaged her against Trump, the party doesn't have anyone better for the job—at least not at this time.

As FiveThirtyEight's Nate Silver points out, Sanders has a clear advantage in that "[he] has run before and won a lot of votes before." This is important, especially in the new Trumpian political era where the idea of what an "electable" candidate looks like has been turned on its head. Sanders naysayers might have muttered about his Jewishness affecting his 2016 chances, but if a pussy-grabbing, blustering dumbass can earn over 60 million votes in a national election, so can a Jew. (Full disclosure: I am also a Jew.)

Sanders's age is the biggest cause for concern, but it's not enough to disqualify him. All the other likely candidates have problems of their own. Former vice president Joe Biden is nearly as old as Sanders and does't have the same built-in base. Senators like California's Kamala Harris and New York's Kirsten Gillibrand are younger but have much smaller national profiles. (Gillibrand's pro-gun and anti-immigration past could negatively affect her 2020 chances.) Massachusetts's Elizabeth Warren is also a strong contender, but has trailed Sanders consistently in much-too-early 2020 polls.

But what really separates Sanders from the pack is that he is a clear vision, something his 2016 primary opponent lacked. As Vox's Matt Yglesias points out, "The fundamental glue that holds it together is the ongoing potency of Sanders's crusade for a single-payer health care system." His "crusade" has been effective in that it's mainstreamed the notion that everyone has a right to health insurance. That, along with his larger message of economic justice, is what makes him so compelling.

As Sanders wrote in a recent New York Times op-ed, "The Democrats must develop an agenda that speaks to the pain of tens of millions of families who are working longer hours for lower wages and to the young people who, unless we turn the economy around, will have a lower standard of living than their parents." That's a powerful message.

Though his age is a concern, it's impossible to deny his potency. And if he decides not to run—or loses out in the primaries—Democrats should hope whoever ends up on the 2020 ticket preaches similar ideas with as much clarity and passion as Sanders does.