I believe they will try and make a come back in the second half. It's not going to be a piece of cake thus they will have to fight for the win. They did miss some good chances but they have to turn them into goals. Goals is all that matters
Anything less than that and this season La Liga is Barcelona's trophy to lose.
From my observation, many opportunities were wasted by Real Madrid players so they had to concede two goals in the first half. Leganes was indeed unstable and unable to play consistently, but when facing big teams they played quite neatly and even Barcelona and Atletico Madrid lost to them. Luckily entering the second half Real Madrid began to increase the intensity of their attacks so they were able to score two goals to get three full points in the match so they avoided a defeat that could make it difficult for them to catch up with Barcelona in the remaining matches.