As in most of Philadelphia's suburbs, the brand of Republicanism practiced in Montgomery County for much of the 20th century was a moderate one. As the national parties have polarized, the county's voters have increasingly supported Democrats at the national level. After voting for the Republican presidential nominee in all but one election from 1952 to 1988, Lyndon Johnson's landslide in 1964, Montgomery County residents have voted for the Democratic presidential nominee for the past seven consecutive elections, with the margins progressively increasing between 1992 and 2008 to 21.8%. The Democratic victory margin decreased in 2012 back to 14.3%, but rebounded in 2016 to 21.3%.