Chicago Mayor Rahm Emanuel officially backed Hillary Rodham Clinton’s prospective presidential campaign on Friday, calling the former secretary of state “a champion for the American people.”

Emanuel, a former political adviser to President Bill Clinton and White House chief of staff to President Obama, has signed up with Ready for Hillary and will host two Chicago fundraisers for the pro-Clinton superPAC on June 5.

“Hillary is smart, she’s determined, and most importantly, she is a champion for the American people,” Emanuel said in a statement released Friday morning by Ready for Hillary. “I’m proud to make my support for her official, and I’m even prouder to join more than two million Americans encouraging her to run.”

Ready for Hillary is building a list of Clinton supporters, which now totals more than two million, to lay the grassroots groundwork for her should she choose to run for president. During the 2008 Democratic primaries, Emanuel, then a congressman, stayed neutral, torn between his long allegiance to the Clintons and his friendship with Obama, a fellow Chicagoan.

In his statement, Emanuel added, “When I worked with her in the White House, I saw what an effective leader she was – like when she spoke out on women’s rights in Beijing and when she played an instrumental role in passing the Children’s Health Insurance Program. I’ve seen firsthand how Hillary has inspired women and men, and girls and boys, here in America and across the globe, and I know that as president, she would continue to move our country forward.”