Consider switching to Bioguide ID as primary key for legislators

[GPHemsley]

Going through unitedstates/congress-legislators, it seems in the olden days there was something of a 3-way tie among bioguide, govtrack, and thomas IDs as primary keys.

Nowadays, though, it seems that most sources have standardized on bioguide. (Indeed, it has been recommended has a primary key for newcomers for a while now.) Thomas no longer exists, having been replaced by Congress.gov, and is thus no longer generating new IDs. Only lis and gpo IDs appear to still be used in most legislative contexts, and even then they tend to be accompanied by bioguide ID.

It might be a worthwhile endeavor to migrate govtrack IDs to bioguide IDs to further standardize and simplify cross-references.

[JoshData]

Bioguide IDs are not always minted fast enough when there are new legislators.