Is there research to support the claim that "expanding the electorate" is an unworkable strategy?

Question

Bernie Sanders claimed that "expanding the electorate" is a viable strategy for winning the 2020 presidential election.

Even more importantly, they could prove Sanders’s theory of winning elections: expanding the electorate and getting traditionally neglected groups to turn out. Some might call it a political revolution.

"To defeat Donald Trump, the simple truth is we are going to need to have the largest voter turnout in the history of American politics — that’s a fact," Sanders said at a recent rally in Exeter. "That means we are going to have to bring people into the political process who very often have not been involved in the political process."

In an interview during the Nevada 2020 Democratic primary, James Carville was asked "about the risk and down-ballot races under a Sanders nominee". Carville responded, in part, by denying that "expanding the electorate" is a viable strategy for winning the presidential election.

The entire theory that by expanding the electorate [] -- increasing turnout so you can win an election [--] is similar to a climate denial. When people say that, they're as stupid to a political scientist as a climate denier is to an atmospheric scientist.

Carville's use of "entire theory" suggests he was not referring solely to Sanders's candidacy.

Some believed that expanding the electorate was a viable strategy for the "rust belt". It may have been successful: Joe Biden Wins Presidency After Recapturing Rust Belt States (this article makes no claim to that effect).

Other Democrats believed [...] that the party should devote its energy to expanding the electorate by mobilizing young people, voters of color and others who look like the country’s changing demographics.

Some claimed that "expanding the electorate" would allow them to win, yet failed. Concerning Texas,

We have a plan to win. One of us, Tory Gavito, runs a data-driven voter empowerment fund that has a track record of expanding the electorate and winning elections.

Is there research to support the claim that "expanding the electorate" is an unworkable strategy per Carville, or does the research dispute the claim?

Answer 1

The article you refer to isn't a general discussion of strategy, it is completely about Sanders. I'd read it as a "hack-job"; it is intended to attack a particular candidate on a topic in which they (are perceived to be) weak.

This was written back in February 2020, with a large number of Democratic candidates still in the race. A big issue at the time was "electability". Because Trump was so divisive there was a sense of "we must win". People looked at 2016, and thought that Clinton had been unelectable, and didn't want a candidate that would lose.

This whole piece is about attacking Sanders on the topic of electability.

Sanders's claim is that he was electable, not by being a moderate candidate that would attract centrist voters, but by being a radical candidate that would get large numbers of people who had never voted before to vote for him.

There are several issues with this: firstly attracting floating voters is more effective since every voter you switch is worth 2. Every time someone switches their vote it means both one more for you and one less for the opponent. A 6% gap can be overcome by switching the votes of just 3% of the voters. But if you are depending on attracting new voters you need to change more minds. Secondly the very policies and campaign style that could attract the non-voters can also put off floating voters. If you attract one new voter, but cause another to switch to the opponents, that is a net loss. And the floating voters are much more easy to reach. They are actively looking for a candidate, and so will look at election literate or watch debates. The non-voters are not, so campaigning among them is harder.

So Carville perceives "electability" as factor on which Sanders is weak, and his favoured candidate (Buttigeig?) is strong. So he attacks Sanders on this topic.

He overstates his case, clearly attracting new voters is a strategy. With turnout at 60-70% there are plenty more non-voters than the gap between the candidates. But Carville isn't presenting a balanced presentation of a political idea. He is attacking his political rival.

Don't read more into the article than that.