Isn't the percentage of the population that is Minmatar in the Federation massive?
Internment camps won't be an option. full scale revolution and losing some systems to them would be...
A third (or is it a quarter ?) of Gallente population is of minmatar ascendency. The fact that the Federation hasn't already faced an uprising probably means that a lot of them don't feel any kind of loyalty toward the Republic, and maybe even don't consider themselves minmatar : just Gallente citizens.
I'd really like to know more about gallente laws on this matter. In France, taking into account anything else that your citizenship isn't only illegal, but downright unconstitutional. From a strictly legal standpoint, the colour of your skin, where your ancestors came from, whatever ethnic genetic markers you may have, your religion, aren't at any moment taken into account. A statement like "There are x% of [insert ethnicity] prisoners in France's jails" should be impossible to make. This system isn't perfect and generates some problems, of course. It can be read as an standardization attempt and does little to prevent daily racism.
It's my understanding that the US legal system on this matter is fairly different : african-american, native american and such are legal denominations. It certainly solves problems and creates others.
I'm not sure what is the option chosen for the Federation : depending on it, how the minmatar living in gallente space will be treated and will react could be very different.