This is what happened when the Franco regime was replaced with ‘democracy’. Conservative Spaniards knew the communist left still existed but were afraid of the regime. As soon as the left was allowed to freely circulate they began plotting to take over the country. The lesson is the left never really gives up unless most are killed.
Left and right have alternated in Spain since Franco. Many of what may seem like leftist policies - such as the welfare state and the national health service - were actually put in place by Franco. European ideologies and party platforms dont map too well to US ones.
The right is very likely to take over after the next election if the PP (Partido Popular, something like the US Republicans, started as Franco supporters) form a coalition with Vox (genuinely far right, grassroots Trump +++). Vox took a huge chunk of votes over the last few years from the PP.
There is a faction of the Spanish judicial system known for sometimes absurd activism, and the structure of it (where judges can investigate and prosecute) allows for “entrepreneurial” investigations and prosecutions, but on the whole it is extremely conservative. The Spanish “deep state” is actually conservative, not liberal. That is why the capital, Madrid, home of the bureaucracy, is a PP stronghold.