The Republican party has not been the party of Lincoln since the 1970s. The Republican party has not even been a conservative party since the 1980s. 

Ever since the 1970s when Richard Nixon finagled the Southern Democrats, the Dixiecrats as they were known, to leave the Democratic party and join/take over  the Republican party. it has been a reactionary right wing neo-Confederacy  party. 

The Dixiecrats left the Democrats because of the northern Democrats commitment to civil rights and abolishing American apartheid in the American south.  The Republicans are the party of Jefferson Davis, first and only President of the Confederacy.

Ironic, since the Republican party came into existence as a conservative party to fight slavery and  destroy the right wing, caste system,  and regressive social structures of the Confederacy.