Following his better-than-expected debate performance last month in which he blasted fellow Texan Beto O’Rourke on immigration policy and garnered national media attention for doing so, Democratic presidential hopeful Julián Castro could focus on a new target, former Vice President Joe Biden, during Wednesday night’s debate in Detroit.

Castro, who exposed a divide in the Democratic field at last month’s debates when he proposed decriminalizing border crossings, could attack Biden now that O’Rourke is not onstage for night two of the second round of debates hosted by CNN.

On the debate stage last month, Biden was asked about the deportations of more than 3 million people under the Obama administration, and he said, “President Obama, I think, did a heck of a job.” But, Castro, who worked as Obama’s Housing and Urban Development secretary, told reporters at an annual convention of the League of United Latin American Citizens earlier this month that the Obama administration went too far on immigration.

“I have learned the lessons of the past,” Castro said at the convention. “It seems like Vice President Biden hasn’t.”

Castro will need to stand out at Wednesday’s debate — and attacking the front-runner could be the way to do so — as he looks to boost his polling numbers and meet the Democratic National Committee’s requirement to participate in the September debates of achieving 2% in four qualifying polls. He already has satisfied the 130,000-donor threshold.

Joining Biden at the center of the debate stage Wednesday night will be U.S. Sens. Kamala Harris of California and Cory Booker of New Jersey, who have both forcefully criticized the former vice president about his voting record on racial issues. Booker last week called Biden “an architect of mass incarceration” for his role in crafting a 1994 crime bill.

A slate of lower-polling candidates, including entrepreneur Andrew Yang, U.S. Sen. Kirsten Gillibrand of New York and Washington Gov. Jay Inslee, will also fight onstage Wednesday for a chance to debate in the fall.

The debate will kick off at 7 p.m. on CNN and will be moderated by the network's Dana Bash, Don Lemon and Jake Tapper.

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