California Sen. Kamala Harris, who was among dozens of speakers at the packed Women's March on Washington, struck a defiant tone in her words to the sea of people dotted with pink hats."When I&nbsp;look at this incredible crowd today I know one thing ... even if are not sitting in the White House ... even if you don't run a corporate super PAC ...&nbsp;you have the power and we the people have the power," she said.Consistent with the theme of other speeches at the event, Harris emphasized that all issues are women's issues."We are tired as women of being relegated to simply being thought of as a particular constituency or demographic," she said.California's newest Democratic senator, sworn in less than three&nbsp;weeks ago,&nbsp;acknowledged that a difficult road lay ahead for the issues important to the marchers, but she was also optimistic."It's going to be harder before it gets easier. I know we will rise to the challenge and I know we will keep fighting no matter what," she said. "This was a day for us all to come together in our nation's capital ... let's buckle in because&nbsp;it's going to be a bumpy ride."