alt Hacker NewsTalk about a pipe dream. This is a far less significant penalty than what has been applied to Russia and absolutely nothing has happened to Putin.
Europe could apply all the same sanctions to the US that it has applied to Russia and Trump would still serve out his full term.
There are differences though. First the US is still a democracy, so unhappy voters matter (and there are the midterms which is an opportunity to express unhappiness). Second the ties between Europe and US are greater than they were between Europe and Russia, so probably this could have more impact.