The Republican National Committee was not hacked because it had better defenses than the Democrats.

The R.N.C. did not suffer the fate of the D.N.C.

Based on the fact that Russian hackers broke into the Democratic National Committee and roamed its computer network for months, collecting documents and emails, the D.N.C.'s defenses do appear to have been inadequate. That is not unusual — many government departments and many companies have been successfully hacked.

And the Republican National Committee's own network does not appear to have been successfully hacked, suggesting that its defenses were stronger. What Mr. Trump left out is that a contractor for the R.N.C. that stored older material was successfully hacked, suggesting that its defenses were incomplete.