BOSTON — U.S. Sen. Bernie Sanders is planning to rally with candidates running for city council, school board and the board of aldermen in Somerville and Cambridge.Monday's visit is meant to highlight candidates running in elections nationwide in November who have been endorsed by Our Revolution, an offshoot of Sanders' unsuccessful presidential campaign.Our Revolution Somerville member Rand Wilson says the group has been organizing for months to continue the revolution started by the Sanders' campaign by focusing on more local political contests.