Updated Dec. 14, 2023 12:21 am ETWASHINGTON—The House narrowly approved opening an impeachment probe into President Biden on Wednesday, hours after his son, Hunter Biden, defied a congressional demand to testify on Capitol Hill, marking a sharp escalation in the battle between the White House and Republicans.The House voted 221-212 along party lines to formally authorize Republicans’ impeachment probe, which party leaders initiated several months ago, hoping to add legal and political muscle to the investigation into whether the president had ties to his son’s overseas business dealings. While GOP lawmakers have obtained testimony that Joe Biden before becoming president occasionally met with his son’s business associates, they haven’t uncovered support for those claims or established tha...