You'd think that politics would have little to do with addition and subtraction and ratios and percentages. But people who have spent time marveling at numerical relationships and interesting statistics tend to have much better senses of proportion, correlation, and causality.
It tends to be the innumerate types who cry foul whenever someone points out an inconvenient statistic or skewed distribution. It's innumerate types who are blind to patterns.
The problem is, people who major in political science and journalism tend to be the types who did better on their verbal than on their math SATs. Their specialties are justification and obfuscation and labeling those who would draw conclusions from numbers as evil.
People who are comfortable with numbers, who actually enjoy delving into statistics, have a much more realistic sense of things. They know which examples are typical, and which are exceptions. They know what to expect, and what not to expect.
They understand odds, and probabilities, and have a better sense of where spending money works and where it doesn't. And they place smarter bets as a result. (It's called common sense.)
They understand what bell curves represent, and how overwhelming some behavioral correlations are. They have a better sense of how people differ.
They have a much better sense of cause and effect, and are less susceptible to the kind of brainwashing which demands you ignore hard numbers. Their opinions are grounded in hard reality, not ideology.
More importantly, they can pick out the relevant statistics, and know when they are being manipulated by misleading handpicked statistics.
Numerate people simply have their feet planted much more firmly on the ground. Innumerate people, less so.
This is a correlation you'll see time and again -- if you're comfortable with numbers.