The tag presidential-election has been used for both the US 2016 presidential election and the 2017 French presidential election. I find this not only ambiguous, but worse still, I find it confusing, because you'd expect "presidential election" to refer to only one specific presidential election.
Do elections for a president in one country have much in common with elections for a president in another country, beyond what two elections in any two countries of any flavour, presidential or non-presidential, would have?
I'd rather have a tag for a specific position (eg "us-presidential-election"), or abandon it and only use "specific-elections".