When former two-term U.S. Rep. Joe Sestak announced on June 23 that he would seek the Democratic nomination for president, his announcement was greeted with surprise — and, judging by his Twitter mentions, even some incredulity. Sestak wasn’t a rumored candidate, and not a single primary poll included him before his announcement. But to his credit, he’s run an active enough campaign to meet FiveThirtyEight’s threshold to cover him as a “major” candidate — although so have 22 other candidates. So Sestak still has a hard road ahead if he wants to break out in such a crowded field.

Sestak is running on a platform of restoring American leadership on the world stage, which he believes touches on everything from national security to climate change. It’s a natural fit for Sestak, a 31-year Navy veteran who served as a defense policy advisor to President Bill Clinton and eventually rose to the rank of three-star admiral. And he thinks those credentials can set him apart from the other candidates, including those of former Vice President Joe Biden, “whose judgment hasn’t always been impeccable when it comes to foreign policy,” Sestak communications director Evan O’Connell told FiveThirtyEight, citing Biden’s vote on the Iraq War.

Indeed, if you’re going to construct a path to the nomination for Sestak, it probably goes something like: If Biden stumbles, here’s another white man with gravitas who can speak credibly to middle America (and doesn’t call himself a socialist). But he has a problem that other candidates in this position (e.g., Sen. Michael Bennet or Gov. Steve Bullock) don’t — he’s made a lot of enemies in the Democratic establishment. In 2010, in defiance of party leadership, Sestak primaried Sen. Arlen Specter, who had recently switched parties from the GOP. Although Sestak impressively came from behind to topple Specter in the primary, he lost the general election by 2 points, and some Democrats blamed him for blowing a winnable race. So when he tried for a rematch in 2016, party elders recruited another Democrat, Katie McGinty, to block his path, and she handily defeated him in the primary. That was the last time Sestak ran for office — until now.

O’Connell wouldn’t say which specific constituencies within the party Sestak would try to woo, but his campaign strategy so far has been focused on retail politics — shaking hands at parades and convincing one voter at a time — in Iowa. But Sestak also plans to tap his old donor base in Pennsylvania, which raised millions for him in his previous campaigns, although O’Connell acknowledged that presidential fundraising will be a challenge because of Sestak’s late entry into the race. Without question, Sestak is starting from behind: Since 1976, only one successful nominee, Bill Clinton, kicked off a campaign later than April of the year before the election. And with only 27 percent of Democrats having an opinion of Sestak, according to a recent YouGov poll, he can scarcely afford to get a late start. However, he didn’t do so by choice: O’Connell says Sestak would have jumped in the race much sooner, but he didn’t want to run as long as his daughter was undergoing treatment for brain cancer. (She was given the all-clear earlier in June.)

Sestak was always going to have an uphill climb. He hasn’t won an election in nine years, and long layovers between campaigns can make for weaker candidates. It’s also hard to win a nomination without at least some support from the party establishment, which he seems unlikely to get. Finally, he has yet to reach 1 percent in any poll, which is a severe handicap to his chances of making the stage for future debates (not to mention getting enough votes to win the nomination). Unfortunately for “Admiral Joe,” on-the-ground campaigning simply may not reach enough voters to make up for that.