Our objective as a society should be ensuring that ALL American citizens over the age of 18 are able to vote without obstacles. The only exceptions would be those who are of such unsound mind (severe mental illness, dementia, etc.) that they are literally unable to fill out a ballot, and convicted criminals who are serving their sentences (and there’s a separate argument that can be made about that). Democrats support the right of everyone to vote, no matter who they vote for.
If every American constitutionally eligible to vote is permitted to vote, and all voters have an equal voice, Democrats would win more elections than Republicans, because there are more Democrats than Republicans.
Which is why Republicans find it necessary to take away certain groups’ right to vote by making it as difficult (and sometimes, impossible) as they can, just by increasing the number of unnecessary hoops one has to jump through. The only way they can win elections is by cheating.