Liberal activist groups have more than 200 “house party” events planned across the country this weekend as part of an effort to get Sen. Elizabeth Warren, Massachusetts Democrat, to run for president in 2016. The “Run Warren Run” campaign, comprised of members from the groups MoveOn.org, Democracy for America and Ready for Warren, is planning more than 200 “organizing house parties” in 46 states, Washington, D.C., Puerto Rico and Guam to try to develop ideas for how they can convince her to run.