Constitutionalism is the ostensible faithfulness with which constitutions are adhered to in letter and spirit. Constitutionalism has a strong streak in the UK, US, Canada, Australia, and New Zealand.
In the US, a supreme court insulated from political pressure can overturn any act of government it finds unconstitutional. Britain has only had a supreme court since 2009 but has centuries of tradition in court impartiality to politics.
Even in the foregoing countries, governments take unconstitutional measures during declared national emergencies. The UK held no elections during World War 2. The US stole the property of Japanese Americans and held them captive for the duration of that war.
Constitutionalism has been wobbly in France. In the 20th century, France had 4 constitutions and 9 different electoral systems. The party in power manipulates the media to its benefit, and French embassies aboard have committed electoral fraud in absentee voting. Aside from these cynical measures, thrice in the 20th century French military leaders abandoned democracy altogether and attempted to seize power. Twice they were successful.
Despite its tepid embrace of constitutionalism, France is shiny compared to most states in the world. China under Mao Zedong showed revolutionary zeal in producing ~65 million corpses of its own citizens. Later Chinese leaders displayed similar savagery, though not with such an imposing body count.
Examples abound of states around the world showing as much respect for their constitution as they do toilet paper. This is particularly true of those led by right-wing military leaders, but it also occurs in ones ostensibly democratically elected.
As American president, Donald Trump treated constitutionalism, and decency, as alien concepts, preferring instead mendacity. Only the courts made any attempt to keep him in line, while the Republican-controlled Congress merely cowered, unwilling to deal with the malevolent miscreant that hijacked the Republican party with his successful presidential bid.