It Would Produce A Shock In The West.

But in Russia, finally, another huge step is made away from globalism. For decades in Russia it was known to everyone that without ethnic Russians (Russkie, as opposed to Rossyane--merely Russia's citizens) there would be no Russia. It, finally, will be reflected in the Constitution. The Amendment by Putin and supported by Committee of Duma sounds like this:

"Государственным языком Российской Федерации на всей ее территории является русский язык как язык государствообразующего народа"

Translation: The State language  on all territory of Russian Federation is Russian (Russkii) language, the language of the State-founding people.  

For the first time, Russians (Russkie, not Rossiyane) are called what they really were and are in Russia's history--a state-founding people. This is huge. Russia has something like 100+ ethnicities populating it, but largest by far (around 80%) are Russians (Russkie), people of Russian ethnicity and culture. Well, Ravil Gainuddin, Russia's Chief Mufti, was against this amendment, but before he expressed his displeasure, he should have asked himself who, for a millennium held Russia together and how Russian state came into existence. Many ethnicities under Russia were not only preserved but were given an unprecedented access to education, healthcare, social status. Gainutdin, being Tatar has to recall how many Tatars, or Bashkirs advanced to the highest positions in historic Russia's institutes of power, science, culture and other crucial fields. Same goes for many peoples of Caucasus. Enough to recall Yunus Bek Evkurov, today a Deputy Minister of Defense of Russian Federation, he is Ingush. Scores of Azerbaijanis, Avars, Armenians, Jews and others live in Russia and their rights and cultures are reliably defended. Islam, in Russia, is declared one of the major religions. 

Basically, Putin did what was supposed to be done long ago--he fixed a historical position of Russkie of which everyone in Russia is well aware and, bar some few crazy exceptions, not only are content with it but want it to remain so for as long as possible. In the end, it is simply a norm in Russia for centuries to do STEM, as one example, in Russian language. I would say, explaining Riemann folds or partial derivatives is done better in Russian language than in, say, language of Russian North's native peoples--it is just a hard cold fact. I can only imagine how such an amendment which puts White European stock people as American state-founding people whose language is English would be met in the United States. As we all know today, the United States was "founded" by people of color, who were mostly gay or transgender, spoke a variety of languages (not English), while white European population of the United States contributed almost nothing to this country, right? Can you imagine designating Swedish people and their language as the foundation of Sweden? Impossible. But Russians, being backward barbaric people decided to do this using outdated, useless and intolerant method of putting interests of the overwhelming majority of people, including huge number of non-Russians, above aspirations of a minority which tries to call white black, wet-dry, and a sunny day an overcast.   

UPDATE: Ravil Gainutdin, actually already issued a statement (and I give him a benefit of a doubt here) that his "disagreement" was not with the principle but with formulation. He emphatically stressed the necessity to point out the state-founding character of Russian people and language and quoted his version of an amendment:

«Выражая волю многонационального народа Российской Федерации и русского народа»

Translation: Expressing will of multi-national people of Russian Federation and Russian people.  
We'll see, as you might expect Russian "liberda" and svidomy Sumerians from Ukraine are going apoplectic from all that. Good.