The gap between Real Madrid and Barcelona is not that big. You may have forgotten the time when Real Madrid had a gap of 6-7 points with Barcelona. But Real Madrid has reduced that gap and surpassed Barcelona. Although there were many matches left at that time, it is still possible for Real Madrid to rise to the top. The gap of just one match can change the points table. In Barcelona's best time, we may not be able to remove Barcelona from the top spot, but we will see a tough fight. It is very difficult for Real Madrid to win this fight if they are not lucky.
The gap is indeed very close, but it could become even more difficult for Real Madrid to claim first place because Barcelona has looked quite consistent lately. Also, there is still the El Clasico match where Barcelona will play as host this time. Real Madrid have been beaten twice this season, and that's no joke because Barcelona completely slaughtered them (2-5 and 0-4). So you can imagine how tough the fight was for Real Madrid as this time they will play as guests.