This system appears to be quite good, but it is still easily gamed.
Let's say that one group (Without loss of generality, kikes) want to control the government. Let us also assume that they have a lot of money.
Kikes can easily provide a financial incentive to Civilians in order to undergo the community service required to become a Citizen. Moreover, they can selectively provide this financial incentive. This enables them to flood the voting pool with their own people. Thus, with minimal effort, they can gain control of the government without too much hassle, especially in a country with only a small number of Citizens relative to Civilians.
The issue is that you have actively reduced your voting pool, which improves the effectiveness of certain flavors of attack. In particular, an attack by numbers becomes more effective if you reduce the voting pool by as much as this reduces it.
Theocracy prevents Jews from infiltrating, by definition. That said, Theocracies have sufficiently many flaws that we should outright discount them.
Of the Democratic systems, those with large numbers of modestly informed voters are more resistant to the problems that Jews bring.
suggested Timocracy. This is outright idiotic: Jews tend to be rich, and tend to be the sorts of people who would buy land and pretend to do productive things on them just so they can get a vote. That is, Jews would overrun such a system so easily that it's not exactly funny. Similarly, systems with an excessive number of uninformed voters are also prone to Jewish manipulation: Jews control the media, and thus control the uninformed voter. This combination suggests that we desire a system with a large number of voters who are also not easily manipulated.
Thus, I propose that given a Democratic system, a somewhat small step beyond basic education be required as a prerequisite for voting. This step should be incredibly basic, so that a person of average intelligence should be capable of clearing it with ease, while a person whose intelligence is in the bottom 25% should be capable of clearing it with notable effort.
I would suggest the requirement of a simple, yet free, government provided course in civics. The course, spanning perhaps half a year, meeting perhaps once every weekend (so that there are 25 classes) would teach to-be-voters the basics of our system, and would be an excellent way to improve our current system, while simultaneously preventing it from being easily susceptible to attacks from large numbers of invaders.
I am not as familiar with non-Democratic systems, but systems where a successor is chosen by a leader are sufficiently susceptible to corruption that I would expect a Jew to overrun them in at least 5 generations.