Yes I see what you worried about and yes that is possible
I think its highly unlikely but its possible
So the US will end up like Russia with "elections " and " opposition " parties but the elections arent free and fair and Putin is guaranteed to win
But to get to that level of subversion of the Democratic process is a long way to go for the US
So for example in Russia ( and all these factors play a part in Putins single party rule sustainability )
You cant seriously publicly criticize the state or the war : In the US public criticism of any government and its decisions occurs on a daily basis
People protest all the time in the US and these protests are often about issues with something government has done
In Russia there is no independent media so the official media narrative always supports the state : In the US there is only private sector and independent media. Its mostly partisan influenced but the media constantly raises issues with the government depending on the political views of the media
Russia has no separation of the judiciary from what the state wants, any law Putin wants the judiciary will rubberstamp. You also wont find things like successful class action suits in Russia against the state
States in the US still have vast degrees of independence from the federal government. Lots of examples of this in the US like R vs W
During the elections in the US citizens are literally bombarded with political and endless partisan advertising and media focus on how terrible one party is or how failed the current President is. This is almost non-existent in Russia because of the lack of independent media so the average Russian citizen isnt exposed to much media criticism of Putin or his policies during the electoral process
And finally the US does have free and fair elections, people do vote and you see leadership change all the time in the US. This doesn't exist in Russia, Putin will never lose an election
As I mentioned I understand your concern and its valid. But the US has a long way to decline around its Democratic reality to end up like Russia but its definitely worth watching