Detroit (CNN) New Jersey Sen. Cory Booker used his second appearance on the presidential debate stage to throw attention-getting punches at the early front-runner, former Vice President Joe Biden.

But he laced his repeated attacks with humor and memorable one-liners that seem likely to differentiate the former Newark, New Jersey, mayor from the nine other candidates who faced off during second night of the CNN debates. And when Booker faced an attack on his own record -- from Biden -- he deflected it with one of the most memorable lines of the night.

"There's a saying in my community that you're dipping into the Kool-Aid and you don't even know the flavor," Booker said to Biden, when the former vice president criticized his tenure as mayor of Newark.

Booker, who has trailed his Democratic rivals in polls and fundraising, also delivered an impassioned argument that voter suppression by Republicans and the Russians led to President Donald Trump capturing Michigan's 16 electoral votes by the narrowest of margins in 2016.

Booker, one of two black candidates on stage Wednesday seeking the Democratic nomination, is eager to win over black voters, and early polling shows them favoring Biden, who served as vice president to the nation's first African American chief executive. On Thursday, as he works to shore up African-American support, Booker kicks off in Detroit a tour of cities with significant black populations in key swing states for Democrats.

Read More