Yes but those numbers are not even remotely comparable.
What if 100% of the American population voted? Would that change the elections at all? Only if the people who don't vote are primarily of one particular political leaning.
Why don't people vote? One reason is when they think their vote is pointless. For instance if you're a liberal living in a highly conservative state, you may not bother to vote in state elections because you think there is no chance of your guy winning. So why bother?
Germany has something like 5 major political parties. So an individual may feel more impetus to get out and vote for his guy because the vote seems less pre-determined. But then none of those parties win a majority and instead have to form coalition governments where they make compromises on the fine points of their individual platforms.
You can think of the Democrats and Republicans as pre-formed coalitions. The main problem with the Republicans since Reagan is that they have become ever more narrow in their platform. That leaves a very large shaped hole for political/economic conservatives who are nonetheless progressives when it comes to science, social programs, etc.
For instance looking at Nixon
He's practically a liberal compared to Bush.
So in my opinion the real problem is those economically conservative voters who hold their nose when they pull the R lever.
Seems to me the Democrats can go a long way towards breaking the monolithic Republican party by simply running a centrist candidate in 2016. As the Republicans continue to act like assholes, like with this letter fiasco, they will piss off traditionalists who will see it as a sign of disrespect for the long traditions of our government.
But they will probably run Hillary Clinton. I respect her and I think she did a great job in the State Department, but she is just as much if perhaps not more of a polarizing figure than Barack Obama.
What we need is another political schmoozer like Clinton who knows how to politically smack down people like Tom Cotton.
I hope Biden runs. I remember how he spanked Rand Paul in their debate.