The Obama administration didn't respond more forcefully to Russian hacking before the presidential election because they didn't want to appear to be interfering in the election and they thought that Hillary Clinton was going to win and a potential cyber war with Russia wasn't worth it, multiple high-level government officials told NBC News.
"They thought she was going to win, so they were willing to kick the can down the road," said one U.S official familiar with the level of Russian hacking.
The administration did take action in response to the hack prior to the election. In September, President Obama privately confronted Vladimir Putin about the hacks at the G-20 summit in China. He warned the Russian President of unspecified consequences if the hacks continued.
On Oct. 7, the Department of Homeland Security and the Office of the Director of National Intelligence issued an unprecedented joint statement pointing the finger at Russia, saying hacks of U.S. political groups and individual politicians could only have been done with the authorization of "Russia's senior most" officials and that its intent was to undermine the integrity of the election.