And more importantly, FPTP doesn't allow for middle ground. If you are in the middle, you can't get elected, because neither party would nominate you.
I'm not sure that's true, at least in the UK, when one of the established two parties moves to the centre ground they tend to win. Moving away from the centre ground is how they lose.
The typical pattern is starting at the edge during the primary then shifting to the center during the general. Making it back to the center is indeed a good path toward success, but makes commitments during the primary much less credible and give the impression that the candidate is just saying what will get them elected. Overall this is terrible for voter trust in elected officials.
