Voter registration contains the updated ID (in most cases, +/- a few dead people). If you know somewone who is registered but is not going to vote, AND you want to risk going to jail, you could try to vote for that person without bring your ID. But people who've done this have gone to jail. Let's say you know 10 people you want to impersonate at the polling stations, you have to select times and places where the same polling volunteers won't recognize you and try to vote in those areas. Let's say there is a highly organized group that keeps track of who votes and who doesn't vote, and then tries to get others to vote for the non-voters, in specific districts, at specific times, for specific people who might not be recognized by a neighbor volunteer at the neighborhood polling station.

In all of these scenarios, the impact is at most a few hundred votes, not nearly enough to help develop a 7% majority in a country. It just doesn't work, is not worth doing, and there are cases of people going to jail who tried it.

It's easier to hack the voting machines, which is where we should look. This happens in every election.