This makes the most sense. They've been going on about voter fraud, practically begging to be countered with hard evidence. Also considering Trump's first lawyer making an admittedly weak case, it allows them to go on with this farce. They could've continued gaslighting and ignoring the fraud but they aren't.

It seems based on what I've seen that it isn't exactly backfiring, just the protests are getting more aggressive. The former US ambassador said earlier today the military "won't give in easily."

I think you should wait and see how this impeachment trial goes. There probably won't be a better time to drop any and all evidence they have to make it happen.