Hillary Clinton, 2016 Democratic presidential candidate, her husband Bill Clinton, former U.S. President, and their daughter Chelsea Clinton wave during a caucus night party in Des Moines, Iowa on February 1, 2016. Credit: Daniel Acker/Bloomerg

So sweet! Chelsea Clinton shared an adorable pic of her 1-day-old son, Aidan, on Twitter on Sunday, June 19.

"At 7:41 AM Saturday, our family and hearts expanded with Aidan's arrival," Chelsea, 36, captioned a photo that showed her and husband, Marc Mezvinsky, looking down at their son. "We are blessed."

Her mom, presumptive Democratic presidential nominee Hillary Clinton, 68, posted their own photo a few minutes later on Twitter.

"What a joy being with our new grandson, Aidan," the former secretary of State captioned the pic with her husband, former president Bill Clinton. "So grateful."

Not to be left out, Chelsea's dad, 69, also tweeted a photo that showed him doting on his first grandson, who is being held by his daddy.

"Aidan has made two dads very happy this Father's Day," he captioned the pic. "Hillary and I are thrilled for Marc and Chelsea!"

As Us Weekly previously reported, Chelsea welcomed the couple's second child on Saturday, June 18, tweeting, "Marc and I are overwhelmed with gratitude and love as we celebrate the birth of our son, Aidan Clinton Mezvinsky."

The former first daughter and Mezvinsky, an investment banker, are already parents of daughter Charlotte, 20 months.

Hillary told Us earlier this year that she cherishes her role as "grandma."

"Having this wonderful little person in your life makes you think about the future in a whole new way,” the presidential hopeful told Us in April. "Being a grandmother is the most amazing experience."

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