Clearly you are a staunch Democrat so we'll have to agree to disagree on Ms. Clinton.
I'm not. I'm an independent and always have been registered that way. I supported Sanders in 2016.... however, where I disagree with a lot of my fellow Sanders supporters is in that I'm willing to be honest about what happened in 2016. The DNC ran a surprisingly fair election. When the Russians hacked them and aired their "dirty laundry," I was shocked how little dirt there was.
I mean, Clinton was a long-time loyal Democrat and a valuable friend and ally to many people in the party leadership, and she was facing off against a guy who'd spent his whole career refusing to join the party and spending half his time attacking them. When faced with a contest between one of their own and a man who'd been a thorn in their side for decades (but who now wanted their backing for his political ambitions), I'd assumed they would be putting a heavy thumb on the scale when deciding. So, when the Russians got their hands on private communications and shared, I assumed there'd be all kinds of smoking guns. But there was almost nothing. I mean, literally, it was such scarce pickings that the DNC bashers were left having to gripe about someone telling Hillary Clinton that a debate in Flint Michigan at the height of the front-page water crisis story might have a question about the water crisis there..... which is about as much of a "well duh" attempt to give her a leg up as I can imagine.
Anyway, Clinton wasn't my first choice.... or my second or third, really. But she ran a good campaign and won not because of some trivial back-room maneuvering by DNC people, but because millions and millions more actual voters showed up and voted for her.
None of which has anything to do with President Obama's responsibilities to protect the US from Russian cyber attacks.
But, again, what exactly was he supposed to do about it?
Also, Obama and the Democrats mocked Romney in 2012 for stating that Russia was a threat
The criticism was that he was saying Russia was our
number one geopolitical foe.... at a time when al Qaeda was still a factor. And that was a period when there was still hope we could improve our relationship with Russia. It hadn't yet taken a hard turn towards autocracy (Medvedev, not Putin, was president at the time of Romney's comment). It wasn't yet expanding into Ukraine. So, there was a legitimate question about whether that first-term-Reagan-style "evil empire" rhetoric was a good idea at that time, when we might still hope to coax Russia into a better relationship by focusing on our common goals (like taking down Muslim terrorism), rather than framing them as our number one threat.
Slightly on a tangent here, but I always found it weird that the GOP effectively took the Medvedev interregnum as their moment to stake out an "Evil Empire" position again. Before that, when Russia was being pushed hard toward fascism by Putin, including waging war crimes on Chechnya, the GOP was surprisingly squishy on him, with Bush famously saying he looked into his eye and got a sense of his soul, and concluded he was straightforward and trustworthy. Then later, with Putin back in charge, Trump happily hung out all day in the man's pocket. But, in between, when there was some glimmer of hope Russia wouldn't just be a strong-man kleptocracy, when Putin at least nominally stepped away from the presidency, Romney was sounding the alarm. It's pretty weird.