Editor’s note: Robert M. Alexander is a professor of political science at Ohio Northern University and the author of “Representation and the Electoral College.” The opinions expressed in this commentary are his own. View more opinion at CNN.

(CNN) — More than a dozen Democrats have announced they are running for their party’s nomination and several others continue to mull a bid. The 2020 field will be the most prolific for the Democrats since the 2008 election cycle.

Like 2008, there is no heir apparent and the party is looking to build on its success in the previous midterm election. In 2006, Democrats gained 31 seats in the House and did even better in 2018, picking up 40 seats. Donald Trump’s poor public opinion approval ratings have encouraged many Democrats that the party will be in a good position to capture the presidency in 2020.

Public opinion polls and betting markets suggest that the current frontrunners are Bernie Sanders, Joe Biden, Kamala Harris, and Beto O’Rourke. Interestingly, Biden and O’Rourke have yet to even announce their candidacies. Second-tier candidates include Elizabeth Warren, Cory Booker, Amy Klobuchar, Julian Castro, Pete Buttigieg and Kirsten Gillibrand. John Hickenlooper and Jay Inslee are the latest entrants to the fray.

But Democratic candidates who are not at the forefront at the moment should not feel despair — nor should their supporters.

A look back at the Republican race for the 2016 nomination can be instructive. Republicans had a similarly sizable field seeking the nomination. At this point in March of 2015, Jeb Bush and Scott Walker had separated from the pack, while Donald Trump hardly registered at all among Republican voters.

A Quinnipiac poll conducted in early March found that a majority of all voters said they definitely would not vote for him and a quarter of all voters indicated they probably would not vote for him. This led one pollster to conclude that “Donald Trump gets a rousing ‘you’re fired’ before he even declares his intentions.”

Trump’s fortunes would change significantly once he announced his candidacy in June. He received a strong bounce, capturing support from at least 10% of poll respondents. By the end of the summer, Trump had become the favorite with around one quarter of Republican respondents supporting him. Prior to his June announcement, however, he rarely polled above 5 percent.

Before the first caucuses or primaries, presidential campaigns go through a process of “winnowing.” This process occurs in tandem with what political scientists have termed the “invisible primary.” This primary consists of raising money, gaining endorsements, increasing one’s name recognition, and building a strong grassroots organization. Candidates who fail to do these things are winnowed from the field and may not even make it to the Iowa caucuses next February.

Not surprisingly, the current frontrunners are doing well in the invisible primary. Sanders and Biden have high name recognition and are strong fundraisers — as are O’Rourke and Harris. Booker, Harris, and Klobuchar have done well securing early endorsements.

It is inevitable that in such a large field, many are courting the same voters. Sanders, Warren, Harris, O’Rourke, Castro, Buttigieg and Booker have been leaning on progressive issues with appeal to millennials and African Americans. Biden, Klobuchar, and Hickenlooper have struck a more moderate tone, looking to appeal to centrist Democrats and perhaps disaffected Republicans. Given the animus toward Trump, this strategy could work if it translates to their being viewed as having the best chance to defeat him.

Jay Inslee stands apart from the field as a single-issue candidate. The governor of Washington stated that he is running hard on the issue of climate change. His website actually refers to him as the “Climate Candidate.” Staking out this space will give Inslee a platform, but it is debatable whether it will be enough to gain sufficient support to gain the nomination.

During the 2016 campaign, Trump’s forceful stance on immigration, his status as an outsider, his willingness to attack fellow Republicans, and the free media he received as a result made it very difficult for any other single Republican to gain traction. These factors largely gave Trump his own lane, while Tea Party Republicans (Rand Paul, Walker, Ted Cruz), Business Republicans (Bush, John Kasich, Chris Christie, Carly Fiorina) and Religious Right Republicans (Mike Huckabee, Ben Carson, Rick Santorum, Rick Perry) fought amongst themselves to claim their own space in the crowded field. Although Trump was the frontrunner, 70% to 80% of respondents continued to split their loyalties among the remaining candidates up through the first caucuses and primaries in 2016.

This suggests several things. First, public opinion polls this far out from the primaries might be fun for political junkies but they do little to predict who will win a party’s nomination. Second, a candidate would be well served to find a lane with little competition while others battle among themselves in the crowded field. This could mean that Inslee’s focus on climate change might ultimately serve him well. A similar case can be made among the more centrist Democrats too. Still, Trump’s name recognition and media attention had much to do with his ability to gain traction relative to his peers. The context of the 2016 race also worked to Trump’s benefit. His status as a “political outsider” further set him apart in an environment that was decidedly hostile toward establishment politicians.

Predicting the Democrats’ nominee so early in the process is a fool’s errand. Yet, it is reasonable to forecast several likely occurrences. The nominee will most likely not be the initial choice of a majority of those in the party. How the candidates fare during the invisible primary season will undoubtedly winnow the field. Among those left standing, the candidate who can make the best case that they can defeat Donald Trump will likely earn the party’s nomination. Regardless of the policy differences among the candidates, the ability to beat Trump appears to be the most important criterion Democrats are weighing in their calculus.

The-CNN-Wire
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