No one really is, it has majority support from both sides of politics. Because it would be a change in the system it's used as a wedge by politicians. Addition

No one really is, it has majority support from both sides of politics. Because it would be a change in the system it's used as a wedge by politicians. Additionally they know that it's harder to get out of the vote among left leaning voters, so any extra requirement would be risky in swing states. Democrat strongholds (ie Delaware) already have voter ID.