Putting aside the politics of the situation, how exactly does the DNC continue to get hammered by apparently-malicious actors without making major changes to their information security practices? My understanding is that the hacks are on-going and persistent - after several weeks of this being in the news, and possibly being aware of it for months, why haven't they been able to harden their systems enough to repel at least a few of these attacks?

Or am I completely misinterpreting the news reports I keep hearing from the NY Times, ArsTechnica, etc.?