It is quite comparable actually. We have two rounds as well, the primary and then the general election. In both Trump was given just about zero chance of winning. But that's America's lying liberal media for you.
Considering the left have lost some 900 seats across Europe, Brexit, etc., most of which wasn't predicted by the media in such a large and sweeping scale I would suggest you stop putting too much stock in what your own mainstream media polls are telling you. They are leftist propagandist.
There is a silent decidingly powerful segment of voters, patriots, who were probably moderates 5-8 years ago who are moving increasingly to the right. They don't trust the media, don't take part in polls, and play their political cards close to their chest. They love France and are sick of watching the impotent European leaders currently running things do nothing as the legacy of their ancestors burn and their borders are overrun by a fully retarted violent Bronze Age-esque ideology/religion. These silent voters will be heard on Election Day. It's a lot closer than you think.
That despot Merkel is next. Certainly her self-loathing crew of political cronies have already suffered major loses across much of Germany.
We have primaries here too, if I follow your logic, we then have three rounds.
Le Pen is far right, there will be a tough fight between Melenchon (far left), Macron (center) and Le Pen.
It's not about the French people being against the left... The two, quite moderate, historical parties, which are the Parti Socialiste (traditional left) and Les Republicans (traditional right), are in danger as both of them are very unlikely to get to the second round, both of them not passing would be a historical moment.
So no, it's not about being against the left, people are tired of seeing the same faces, the same careerist politicians, holding the power.
Your view of European politics is very biased anyway, the American political scene is very skewed to the right, your left if our right and your right is almost our far right.