Vladimir Putin was inaugurated for a historic fourth term on Monday. Putin promised to serve his people and his country after taking the oath of office for his fourth term as Russian president on Monday. Putin effectively has been the leader of Russia for all of the 21st century. He stepped down from the presidency in 2008 because of term limits, but was named prime minister and continued to steer the country until he returned as president in 2012. In 2024, when his term ends, without constitutional reform, Putin will not be able to run for a fifth time -- Russian law forbids serving more than two consecutive terms. But what if Putin changes the constitution?