(CNN) - Former President Bill Clinton on Wednesday formally swore in Bill de Blasio as Mayor of New York.
The very public move by the former President appeared to wrap a bow around long-standing ties between the new mayor and both Bill and Hillary Clinton. And it could pay political dividends for the former Secretary of State if she decides to make another run for the White House in 2016.
"It's been a great joy for Hillary and me to see the Mayor's progress," said Clinton, adding that de Blasio "represents, with his family, the future of our city and our country."
De Blasio has a long history with the Clintons. He was a Department of Housing and Urban Development regional director under Bill Clinton, and served as campaign manager for Hillary Clinton's successful New York Senate campaign in 2000.
While de Blasio was overshadowed by others during his tenure as Clinton's campaign manager, he's maintained his links to the Clinton world over the years.
This includes campaigning for Mrs. Clinton during her unsuccessful bid for the 2008 Democratic presidential nomination.
The Clintons stayed out of the multi-candidate Democratic primary for New York Mayor, as the field also included former Rep. Anthony Weiner, who's married to top Hillary Clinton aide and adviser Huma Abedin.
But once de Blasio won the primary, both Clintons supported him. Hillary Clinton headlined a top-dollar fundraiser for De Blasio in October, weeks before his landslide election to become Gotham's first Democratic chief executive in two decades.
And she was in attendance Wednesday as her husband administered the oath of office at City Hall.
"I am sure Secretary Clinton is proud that Bill is now Mayor of New York. He was, of course, instrumental in Hillary winning the New York Senate seat, and she in turn helped his campaign, so the ties are long and strong," said CNN contributor and Democratic strategist Paul Begala, a longtime adviser and friend to both Clintons.
Move could help Clinton in 2016?
If Clinton does launch another campaign for President, she would instantly become the overwhelming frontrunner for the Democratic nomination. But there are some on the left – base voters in the Democratic presidential primaries and caucuses – who are cautious about Clinton and her ties to Wall Street.
Having de Blasio on her side can only help Clinton shore up the party's base if she runs for the White House again.
De Blasio highlighted income inequality as he ran for Mayor, something Bill Clinton supported as he introduced him at the swearing-in.
"I strongly endorse Bill de Blasio's core campaign commitment that we have to have a city of shared opportunities, shared prosperity, shared responsibilities," Clinton said.
And de Blasio's become a hero of the populist left along with Sen. Elizabeth Warren of Massachusetts
"Hillary's close relationship with the new Mayor of New York – and the new darling stalwart of the progressive left – can only help her bona fides as a candidate who will be unwavering in the fight against income inequality and a level playing field for working families who do not feel the economy is working for them even as it continues to get better," said Maria Cardona, a CNN contributor, Democratic strategist, and spokeswoman and adviser for Clinton's 2008 presidential campaign. "If she runs, he will give her added credibility and could give skeptic progressives reason to look no further for another candidate."
And the person that some progressives are looking at is Warren, even though the freshman Senator said last month that she's "not running for President" in 2016 pledged to "serve out" her term, which goes through 2018.
Having de Blasio firmly in the Clinton camp may make some progressives think again.
"The Clinton political family is vast and far-flung and deeply loyal. That can only be a plus – whatever Hillary Clinton decides to do," added Begala.