Which county has had the highest Republican floor excluding third parties?

[mikhaela]

Which county has had the lowest Republican floor when only the Republican and next largest candidate is calculated?

For example in Sevier county Tennessee for 1996 the percentage would be 62.41 since it is only (11,847/(11,847+7,136)).

For 1912, I allowed Roosevelt to take the place of Taft if he got more votes in that county, and in the case where Wilson finished third I ignored Taft.

Ex. (2,411/(2,411+341))=87.61

The only two other counties which haven't gone under 62.41 using this method are

Johnson county, Tennessee
Jackson county, Kentucky

I couldn't find the specific county results for 1876 though.

[mikhaela]

In other words, Sevier county Tennessee has the strongest Republican base of support historically for a metro/micro area county.