With all due respect to Senator Cruz, I think “standing with Ukraine” and being dragged into an all-out war with Russia would be a mistake. What the media is not emphasizing is that many in eastern and southern Ukraine are ethnic Russian, pro-Russia and would much rather be a part of Russia than Ukraine. They want Russia there. This is a very complicated and far more detailed and historical issue than just Russia invading Ukraine.
The West is playing with fire and they will get badly burned if they mess this up.
So, the question is....... how greedy is Putin.
If he merely annexes the Russian eastern areas of Ukraine, he will be allowed to keep them. There will be some wailing and knashing of teeth but little else.
If he crosses some agreed to line in west Ukraine and is greedy, there will be repercussions of some sort. Aside from not inviting Putin to his birfday, Obama might create some financial disruptions.