WASHINGTON, D.C. — Former Vice President Joe Biden, facing a crisis that could hobble his 2020 presidential campaign even before it is launched, Wednesday released a video responding to complaints from women who say they were uncomfortable with his tendency to touch and hug people he meets in politics.

“Social norms are changing,” said Biden, his first comment on the controversy that has surrounded him for days. “I understand that, and I’ve heard what these women are saying.”

“Politics to me has always been about making connections, but I will be more mindful about respecting personal space in the future,” he added. “That’s my responsibility, and I will meet it.”

The controversy about what Biden himself has called his “tactile approach to politics” underscored the new political dynamics in the first presidential campaign of the #MeToo era.

He has been buffeted by questions that first arose Friday when Lucy Flores, a former Nevada assemblywoman, wrote in a New York Magazine web post that she had felt demeaned and disrespected when Biden touched her offstage at a 2014 campaign rally. She said she felt Biden’s hands on her shoulders and froze.

At least three other women have since reported having felt similarly uncomfortable with Biden’s behavior.

Biden at first tried to quell the controversy by having his staff issue statements on his behalf.

Even some of Biden’s supporters have been uncertain and uneasy about where the controversy would lead and whether it would undercut his campaign for the nomination in a party where women are a core constituency and many of his potential 2020 rivals are women.

At the very least, his supporters worry that his behavior has underscored how much Biden, a 76-year-old who was first elected to the Senate in 1972, is a man of another political era during a campaign cycle in which many Democratic primary voters are clamoring for a fresh face.