How might states like California lose representation in the House of Representatives?

The number of representative in the U.S. House of Representatives is fixed at 435. Every 10 years the U.S. Census Bureau takes a census of the population in each state. The 435 representatives in the U.S. House of Representatives is then reapportioned among the 50 states based on the population in each state. Based on the 2010 Census California currently has 53 representatives in the U.S. House of Representatives. The next U.S. Census will be taken in 2020. Based on the results of the 2020 Census, the number of representatives from California could change.