With so many entrants in the Democratic primary field, many observers have wondered what billionaire Tom Steyer's candidacy adds to the race.

Here's one answer: Steyer is a gift to political scientists. His campaign offers us an unusual opportunity to explain why the "reforms" he champions as magical solutions to our political problems are likely to be anything but. Unlike other candidates in the race, who focus on substantive policies — like health care — Steyer is passionate about changing the procedures of democratic decisionmaking. Unfortunately, the ideas he champions are generally bad ones. My field has spent decades amassing evidence that his proposals, and overall approach to governing, would likely make our political system worse, not better.

A hedge-fund manager who recently qualified for the Dec. 19 Democratic debate, Steyer has flooded early primary states with so many ads touting these proposals that even his supporters think he should dial it back. (Months ago, my 13-year-old son could already quote Steyer's YouTube ads word for word.) Few politicians have worked so hard or spent so much to, in effect, troll an entire scientific field.

The problems start with a central rationale for his candidacy: He repeatedly says that only a nonpolitician can change Washington. "The only way we can make change happen is from the outside," he says in a video promoting his reform agenda.

In reality, political science research suggests that Steyer's lack of experience in elected office or government service would hinder his ability to deliver on his promises. The value of political experience has been most closely studied at the congressional level. Research shows, for instance, that members of Congress with experience in state legislatures are more effective at getting federal legislation passed than those who lack this background.

Historical evidence suggests that inexperienced presidents face similar obstacles. Consider the case of Donald Trump, who has less experience in governing than any prior occupant of the White House. Every president struggles to overcome the limited powers of the office, but Trump stands out among modern presidents as especially weak and ineffective. For example, though congressional Republicans fear his tweets, they continue to largely control the legislative agenda. And to an unprecedented extent, the federal bureaucracy and even Trump's own staff often seek to manipulate him and ignore or undermine his directives. In short, being an "outsider" has significant downsides and few direct benefits.

Steyer also advocates term limits in Congress, which he claims will "defeat the corporations who've bought our democracy" by preventing them from, in effect, capturing legislators. "The longer an elected official stays in office," his website states, "the more beholden they become to corporate backers and special interest groups."

First of all, the promise is unrealistic: Steyer's plan would require a constitutional amendment to overturn a Supreme Court decision, U.S. Term Limits, Inc. v. Thornton, that prevents term limits for members of Congress.

More important, however, the evidence is at best equivocal on the effects of term limits. Some studies find they would actually enhance the power of special interest groups. The problem is that incumbents who lack a re-election incentive can reduce the effort they devote to their jobs, becoming less attentive to their constituents and working less on the legislative process. The political scientists Alexander Fouirnaies and Andrew B. Hall, for instance, use data from 1995 to 2016 to show that legislators facing term limits sponsor fewer bills and miss more votes. This shift can increase the influence of outside forces such as interest groups and lobbyists, who will happily fill the vacuum in expertise and effort created by term-limited legislators.

These dynamics played out in California after term limits were enacted in 1990 that restricted members of the Assembly to three terms (six years) and state senators to two terms (eight years). Observers found that these short limits scrambled the legislative process, discouraging legislators from acquiring experience while in office and creating constant turnover in leadership positions. Lobbyists, staffers and other unelected figures seemed to gain power as a result. In response, good-government groups endorsed Proposition 28, which passed in 2012, reducing lifetime limits to 12 years but allowing legislators to serve all of that time in one chamber.

Steyer's other "big idea" is direct democracy. He wants the United States to embrace national referendums, which he claims would "increase voter participation, thwart congressional gridlock, and give the American people more power over their democracy."

But political scientists have considerable doubts about referendums as well. Under some conditions, referendums can have benefits like those Steyer suggests. A study of state elections from 1870 to 2008 found, for instance, that the presence of initiatives on the ballot is associated with an increase in turnout of 3.7 percentage points in midterm elections (which usually bring out far fewer voters than presidential contests). They may also move policies into closer alignment with voter preferences by allowing the public and outside groups to bypass legislatures or making legislators more responsive due to the threat of a referendum (though studies conflict on this point; the relationship is not consistent across issues and research approaches).

Voters frequently lack adequate information about the policies at issue, as we saw in the United Kingdom's 2016 Brexit plebiscite; the proposals on the ballot are often inflexible and poorly designed, as with California's Prop. 13, which created limits on property taxes that have hamstrung education funding for decades; and outside interests can exert disproportionate influence over the process, as Steyer himself has done by bankrolling initiative campaigns in California and states.

Steyer deserves credit for running a campaign of ideas. Unfortunately, they're bad ones. When he tires of spending millions on this ill-fated bid, he'll have more time on his hands. I hope he'll consider taking a class in political science.

Brendan Nyhan is a professor of government at Dartmouth College. He wrote this article for the Washington Post.