More than 200,000 Americans have signed a petition to encourage Senator Elizabeth Warren of Massachusetts to seek the Democratic presidential nomination in 2016, two of the country’s largest progressive groups behind the effort announced Friday.

Democracy for America and MoveOn Political Action announced their joint effort in December and launched a website called “Run Warren Run.” Collectively the two groups claim 9 million members.

“This is Senator Warren’s moment and, together, this people-powered effort is working to build the infrastructure, energy and political momentum she’ll need to seize it,” said Charles Chamberlain, of Democracy for America.