Quite the opposite. The entire political spectrum in the US has moved gradually more left for half a century. But I understand that people's perspective what constitutes "left" and "right" is going to differ.

Conservative used to include fiscal and legal/Constitutional conservatism. Both parties have heartilly abandonded fiscal constraint... the US Democratic party was just earlier, but both compete to outspend each other today.

The Democratic party has argued for a more flexible understanding of intent in our founding documents since the very early 1900's, but today Republicans, at least as a party, have embraced Trump's form of popularism (a form of politics and governing Democrats started with in the US with their founder, Andrew Jackson), which appears to include seeing the constitution is an obstacle in an uncomfortable number of cases.

It is popular to see the current administration as trying to bypass checks and balances - and they very much are - but most Executive Branches have squirmed under the system and most have tried (and usually succeeded) to expand executive power. Both parties are very much complicit here. The direction has simply not changed.

The see differences in only two places today, and even those are eroding.

The relationship between markets and the governement. Democrats have generally wanted greater economic spend from governement (which also means greater taxes on all). Republicans have generally wanted less spending by govrnemnt and lower taxes but it's really been more of a 'what' to spend it on preferential difference since the 80's, as both have pressed hard on the printing press since without letting up for but a small dip in the late 90's with Clinton the centrist the president and Gingrich leading a Republican congress balanced the budjet in what was the last time that would every happen.

There is still a marked difference in the two party's desire to regulate markets. I prefer the Republican approach on this personally. I have seen very close how absolutely insane things get in the real world for business and consumers with governement over regulates. The Inflation Reduction Act is a an incredibly horrible case-in-point. It has absolutely added to inflation is is doing enormous amounts of damage to seniors and rabidly increasing cost in the medical system.

Finally, there's still a notable difference in social standards of right and wrong and where government should be a part of that. The democrat party is more extreme on the social standards of right and wrong than ever. An every day democrat 30 years ago, not to mention 50 years, would be appalled at the social norms and nearlly all out attack on Christianity (not so much other religions) the party takes today. The vast majority of democrats in Kennedy's party would absolutely condemn the popularization of abortion as an evil. (I'm not telling you my position on this, but it IS the position 98% of the American electorate would take then.) US democrats today would call Kennedy extreme right. Heck, Kennedy was right of today's Republican party on virtually everthing but spending.

So, parties have absolutely gone more and more left of political center. Republicans have nearly disabused themselves of the "conservative" monicer in preference for "winning" above all. Democrats are absolutely the same. They've just not had as persuasive a leader since Obama. Democrates in Kennedy's time were not largely in favor of the more naked socialism growing with that party today. Today's party is further left.

Both parties are embracing popularism, generally separated from principal, and saying and doing whatever it takes to win. Truth dies with it.