Volunteer postcarding has become one of the most popular tactics in grassroots organizing. Thousands of people across the country spend their evenings writing postcards to voters they'll never meet, in districts hundreds or thousands of miles away.
If you're new to postcarding, we have a full guide on how postcarding works on this page.
At Indivisible Hawaiʻi, postcarding is a core part of our work to flip Congress blue - but does it actually increase voter turnout?
The short answer: yes. Multiple independent studies confirm that handwritten postcards to voters boost turnout, and the effect is significant enough to change election outcomes.
Small increases that add up
According to research by the Environmental Voter Project (EVP), volunteer postcards using "loss aversion" messaging increased turnout by 1.3 to 1.5 percentage points across multiple randomized controlled trials. That might sound small until you remember that many elections are decided by margins far smaller than that. In 2020, Georgia's two Senate seats were decided by less than 100,000 votes combined. A 1.5 percentage point increase among low-propensity voters could have flipped those races.
Vote Forward, an organization focused on letter writing (similar to postcarding), ran experiments in 2020 and found that handwritten letters increased voter turnout by 0.5 to 0.8 percentage points. Their volunteers sent more than 17.6 million letters, resulting in an estimated 126,000 additional votes in key states. For context, that's almost half the combined margin by which Joe Biden won six battleground states.
A 2018 study on postcarding best practices found that volunteer postcards fall somewhere between commercial mailers and phone calls in effectiveness. They're not as powerful as a phone call, but they significantly outperform mass-produced mail. The study also discovered that postcards work better with younger voters (under 45) than older voters, and that Democratic voters in red states responded more strongly than those in blue states.
Research from Sister District and Postcards to Swing States has shown similar results. An early Postcards4VA study showed that postcards increased turnout by 0.4 percent, comparable to or better than door-to-door canvassing. Postcards to Swing States ran a randomized control study in a congressional district primary and found their postcards increased turnout by 1.2%.
What makes some postcards more effective than others?
Not all postcards work equally well, and the research has pinpointed what separates the ones that move voters from the ones that get tossed in the recycling bin.
The handwritten element is essential. Vote Forward's research shows that voters respond to the personal touch - they can tell when someone took the time to write to them individually versus receiving mass-produced mail.
The message determines the results. The Environmental Voter Project found that "loss aversion" messaging has been the most reliable strategy across multiple trials. These postcards remind voters of their good voting record and encourage them to maintain it. "Trending norms" messaging - showing voters that turnout is increasing and they shouldn't be left behind - looks promising but needs more testing.
Who you target and when you send matters too. The research consistently shows that postcards work best with
- Low-propensity voters who are registered but don't always turn out,
- Younger voters, and
- Voters in areas where they might feel politically isolated.
How postcarding fits into the bigger picture
Postcarding won't save democracy all by itself. Sister District's research notes that handwritten communications like postcarding have small but real effects on voter turnout and registration. The power comes from scale - volunteers can write postcards from home, they don't need extensive training, and they can reach voters across state lines.
Postcards to Swing States (now Progressive Turnout Project) ran the numbers and estimates that their 2024 postcards added approximately 200,000 votes. That's what happens when millions of postcards get written - small individual impacts stack up into election-changing numbers.
So... Is writing postcards worth your time?
If you're thinking about joining a postcarding campaign or wondering whether it's worth your time, rest assured that it works. Multiple independent studies using randomized controlled trials - the gold standard of research - have proven this across different elections and contexts.
It's about quality, not quantity though: a thoughtful, handwritten postcard with effective messaging will get better results than churning out dozens of generic ones. And campaigns combining postcards with phone banking, canvassing, and digital outreach produce the strongest results – sometimes up to 1-2 percent extra voter turnout.
While it's true that a 1-2 percentage point increase in turnout won't single-handedly win every race, in competitive districts and close elections, that margin can make the difference between victory and defeat.
Join us
In an era when elections get decided by razor-thin margins, postcarding is one of the most accessible and effective ways to make a difference.
Indivisible Hawaiʻi chapters across the state host regular postcarding parties where volunteers gather to write postcards together. It's a chance to connect with fellow organizers, share pupus, and make a tangible difference in competitive races across the country. Check out our upcoming events to find a postcarding party near you - or contact your local chapter about picking up a kit to write postcards at home.