We could know Joe Biden’s pick for vice president by the end of the week.Biden, who served as vice president under President Barack Obama, said in May that he would announce his running mate by Saturday, Aug. 1, more than two weeks before the start of the Democratic National Convention.While the convention for the most part will be held remotely this year, delegates still will vote to nominate Biden and his choice for vice president.Biden has pledged to nominate a woman for the position. In the most recent Quinnipiac University poll, Biden held a 15-point lead over Trump, 52%-37%, largely on h…