When Bernie Sanders was mulling a 2020 campaign last year, he said he would likely pull the trigger if he thought he was the “best candidate” to defeat President Trump.

Now that he’s officially in the race for the White House, a key element of his argument is that he is — in a way that flies in the face of conventional wisdom. His campaign is gearing up to take direct aim at one of the central cases made against him: That the 77-year-old democratic socialist, far from being unable to win a general election, could blaze a non-traditional path to victory on the electoral map unlike any other Democratic candidate.

This month, Ben Tulchin, Sanders’ pollster, circulated a memo about an online survey he conducted in late 2017 for progressives who were hoping to flip state legislative seats in West Virginia.The poll found that Sanders would beat Trump by 2 percentage points in the state — despite the fact that Trump won West Virginia, 69-27, and that no Democratic presidential candidate has carried the state since 1996.

To operatives in both parties, the notion that Sanders could defeat Trump in one of the president’s strongholds strains credulity. But the Sanders team is convinced the Vermont senator’s appeal to independent voters, the white working class, and people of color is underestimated — and could pay dividends in unexpected places in a general election. They argue that his anti-establishment and populist economic message, as well as his many years of representing rural voters, makes him competitive in not only the Rust Belt states where Hillary Clinton faltered but also potentially in deep-red states, too.