Former Secretary of State Hillary Clinton took aim at one of President Donald Trump’s greatest insecurities on Sunday, needling him over the lackluster crowd at his Washington, D.C. military parade this past weekend .

The parade was the spectacle event Trump had long wanted. It also helped sparked the largest mass opposition to him since his inauguration 145 days earlier.

The procession, with more than 6,000 soldiers and 128 Army tanks, was one Trump tried to make happen in his first term.

As a military parade rolls through Washington, DC, on Saturday – President Donald Trump’s birthday – millions of Americans are expected to protest in what organizers predict will be the strongest display of opposition to Trump’s administration since he took office in January.