Biden's running mate announcement reportedly pushed back

Joe Biden said he would announce his choice for presidential running mate the first week of August. 

But according to several media reports, that announcement appears to have been pushed back.

According to the New York Times and CNN, the announcement will come the week before the Democratic National Convention, which is scheduled for Aug. 17 to 20.

Several contenders have emerged, including Sen. Kamala Harris (D-Calif.), Rep. Karen Bass (D-Calif.), Obama former national security adviser Susan Rice, Massachusetts senator Elizabeth Warren, and Illinois senator Tammy Duckworth.

The California senator has long been seen as the top contender to be Biden's running mate. However, in recent weeks Bass has vaulted up to the top of the shortlist.