Yes, this is exactly the sort of problem that the EU wants to avoid. Hungary joined the EU in 2004. Since the Fidesz party was elected in 2010, Hungary turned increasingly authoritarian; Fidesz had a sufficient majority to institute a new constitution in Hungary that removed checks and balances between different branches of government, and it turned out that the EU can do very little to counter such developments.
The main ways to sanction governments of EU member states, such as temporary suspending of voting rights in EU decision making, and EU funding, require unanimous approval of all other EU member states, and as soon as you have 2 member states who are afraid of such sanctions they will put in their veto in favor of each other, as has happened repeatedly with Poland and Hungary in recent years.
The main ways to sanction governments of EU member states, such as temporary suspending of voting rights in EU decision making, and EU funding, require unanimous approval of all other EU member states, and as soon as you have 2 member states who are afraid of such sanctions they will put in their veto in favor of each other, as has happened repeatedly with Poland and Hungary in recent years.