Legally: yes, federal law says that you have to be allowed to vote for the federal offices from wherever you last lived in the US (or your American parent, if you were born abroad but never lived in the US)

Reality: some states make it easy and will even let you vote in state and local elections, others make it inconvenient if you’re not with the military (have to request ballots every year, have to diligently watch for registration purges), and some make it practically impossible for non-military.

If you’re an American abroad having trouble registering and/or getting your ballots, your local Democrats Abroad chapter has someone who will help you out. Even if you’re a Republican ;)

I want as many US citizens abroad as possible to vote on a regular basis, even if they’re voting differently from me: our representatives will pay more attention to us if they see that we vote in larger numbers.

Is there a way to, even approximately, target the "social security system" issue with your vote? Or do you have to chose between 2 or 3 bundles of pre-chosen policies, the composition of which you had no say in?