Straight-ticket Vote and Swing Vote in Cruz/O'Rourke Contest for the US Senate in 2018

In preparing a report for ACC's Center for Public Policy & Political Studies, I found an interesting relationship between the straight-ticket vote and the swing vote (non-straight-ticket vote) in the contest between incumbent Republican Senator Ted Cruz and Congressman Beto O'Rourke. In the seven counties that cast slightly more than one-half of the total vote in Texas, here is the relationship between the straight-ticket vote and swing vote in each county for each candidate.

Although the correlation between the straight-ticket vote and swing vote is not perfectly correlated, the Pearson for Cruz is .854 and for O'Rourke is .874.

It is fairly obvious that in these counties, both candidates did well in drawing the straight-ticket vote and the swing vote in the counties that they won.

Here are the results for each of the counties in the graphs:

Candidate	County	% STV	% Swing
Cruz	Harris	44.0%	32.05%
	Dallas	34.7%	29.63%
	Tarrant	53.8%	39.38%
	Bexar	40.9%	38.11%
	Travis	27.1%	20.61%
	Collin	58.2%	41.65%
	Denton	61.7%	37.47%
O'Rourke	Harris	55.3%	66.97%
	Dallas	64.7%	69.35%
	Tarrant	45.6%	59.44%
	Bexar	58.3%	61.89%
	Travis	71.8%	78.37%
	Collin	41.3%	56.90%
	Denton	37.6%	61.39%
Pearson Coefficient		CRUZ	O'Rourke
		0.854109	0.873526

And the Table showing the result in each county:

County	GOP STV	Cruz SV	Winner
Harris	Lost	Lost	O'Rouke
Dallas	Lost	Lost	O'Rouke
Tarrant	Won	Lost	O'Rouke
Bexar	Lost	Lost	O'Rouke
Travis	Lost	Lost	O'Rouke
Collin	Won	Lost	Cruz
Denton	Won	Lost	Cruz