(CNN)When Nathaniel Batchelder, a 28-year-old who has autism, voted Thursday in the midterm elections, "we were on such a high," said his mother, Susan Senator.
Mother's booklet for son with autism: 'Voting is really important. Here's how to do it.'
Batchelder has "a pretty severe developmental disability and a lot of anxiety and communication issues, but he's very eager to learn everything about the world," said Senator, who has written books about autism and lives in the Boston area.
But had he lived somewhere else -- in a state where laws place tighter voting restrictions based on "mental competence" -- he might not have been able to cast his ballot at all, experts say.
Senator knew that she needed to come up with a way to make things as smooth as possible for her son. Batchelder voted for the first time in 2016, but when he voted in this year's primaries, he felt anxious and rushed. He went through a couple of ballots before he was able to fill one out properly.
So Senator created a booklet for her son titled "Voting is really important. Here's how to do it."
The nine-page resource walks him through the process, complete with pictures of the ballot, which he could practice bubbling in, and reminders about the candidates running for different positions.
"Nat uses the pen to color in ONLY ONE CIRCLE: That is how you vote!" the guide says. "What are you going to be? Republican or Democrat?"
His dad read it with him, as did his caregivers -- and right before voting, he practiced filling in the bubbles one by one. For Senator's son, knowing the rules and structure beforehand is key in addressing his anxiety before he can exercise his civic duty.
"For any person, the more you know about how something works, the better you're going to perform," Senator said.
On the final page of her booklet: a photo of a ballot being inserted into the voting machine, with an encouraging note:
"Put the paper in the slot of the machine! You did it!"
Senator isn't the only one trying to develop a voting resource for people like her son.
"Is this something that's easily accessible or known about in the autism world? I don't think so," said Michael Bowman, senior developmental specialist at 3LPlace, an organization that provides support for adults with autism and other developmental disabilities in the Boston area.
Bowman has been putting together a nonpartisan lesson plan for members of the organization that uses a five-point scale indicating where candidates fall on certain issues. When he heard about Senator's booklet, he requested it so that he might incorporate how she described the physical process of voting to her son.
"It's something that we felt that we had to create in order to help empower our members," Bowman said.
Bowman said that many adults like those he works with might have difficulties communicating, but that doesn't mean they have a hard time putting together their thoughts or being informed voters.
For example, when Bowman first discussed marriage equality and abortion, he realized that members initially thought he was asking whether they themselves wanted to marry someone of the same gender or have a baby. So he reframed the questions in order to communicate these issues effectively.
People with intellectual disabilities "rarely receive instruction or other supports to encourage their participation in voting," according to a 2015 survey of people who care for and work with them. Most respondents said they "believed that teaching individuals to vote was important and worthwhile and that instructional materials could be prepared that would allow people ... to understand varying political platforms or positions on at least some political issues."
Some respondents also expressed concerns, saying they were "mindful of the time requirements and the potential for personal bias to influence the instructional process."
Senator said she guides all three of her sons as a parent would, and only one has a diagnosis of autism. Her family doesn't always agree on everything, she said -- but one of the things that's different about Batchelder is that "he's a very black-and-white thinker." In order to have those conversations, she finds ways to be clear and concrete about issues that impact his everyday life.
For example, support from Medicaid allows Batchelder to live in an apartment with caregivers and lead an active life, playing sports, singing in a rock band, volunteering and recycling at a high school, Senator said.
For many people with disabilities, "their livelihood depends on their health care," said Jennifer Mathis, director of policy and legal advocacy at the Bazelon Center for Mental Health Law.
"They have arguably more at stake than many of us."
A number of states have requirements that voters be "competent" in order to vote, which can have the effect of stripping away the right to vote from people with certain disabilities, Mathis said.
The US Election Assistance Commission keeps data on voters removed from registration rolls due to "mental incompetency," but it's hard to say exactly how many people across the country have been prevented from voting due to disability, she added.
"Our problem with those laws is that they hold people with disabilities to a higher standard than all other voters," Mathis said.
According to this year's voting rights guide led by the Bazelon Center, 40 states and the District of Columbia have policies in state constitutions or election laws that could restrict someone's right to vote if they have such a disability.
Often, these policies are based on guardianship status, Mathis said, which may have been imposed after a single episode in which the person was in crisis -- as with someone who didn't take their medications or who didn't have access to services they needed.
"The consequence of that: The person is now living with the inability to make decisions about basic things for the rest of their life," she said.
More restrictive state policies might prevent people under guardianship from voting, while other states have less restrictive policies or ones that are difficult to enforce. Some "middle-ground" states might require some sort of challenge in order to prove "competence" -- for example, by answering questions about the governor's name or issues on the ballot, Mathis added.