Can you link to them? I just don't see Republicans running on and exposing their most extreme views to everyone as a bad thing.
On the one hand, FDR moved the country to the left - it got votes because of the reaction to the Great Depression. Because of this, it pulled the Republicans to the left, as they had to promise to support left-wing things to try to compete - and even that wasn't enough. It gave us more liberal policies like those in several ways under Eisenhower, where 'conservatives' were 'a fringe' without power.
On the other hand, when the country elected 'too far right to get elected' Reagan, who Democrats wanted to get the nomination because he was 'radical right', it pulled the country way to the right, and 'liberal' became not the word describing the country but a word to attack Democrats with, and the Democrats moved to the right to compete, and the country hadn't recoered yet from that shift.
What was the dominant political orientation for decades is now 'far left'.
The way we shift back is not by nominating ever further-right Republicans until people say 'enough' - that got us Obama, a good Republican president.
It's by electing an actual liberal president who can pull the country to the left.
The further to the right the Republicans go, the further to the right the Democrats go simply because it helps win elections.
They're always going to get the 'left' vote because they're better than Republicans; but they can get more and more of the rest of the country the further right they go.
'Centrists' as well are shifted to the right when staying in the middle is between an ever more right-wing Republican party and ever more right Democratic party.
The idea is, a party shouldn't move too far because it costs them votes - but when they do and win, it can shift the goalposts of 'left and right', as with Reagan.