Impeachment inquiry threatens Biden with election-year headache

By voting to formally authorise the congressional investigation into Joe Biden, Republicans in the House of Representatives have started the ball rolling towards his impeachment.

It may be difficult to stop.

Three of the four previous times the House took this step, the chamber ultimately opted to impeach. The one time it did not was because Richard Nixon resigned before a vote could be held.

Republicans allege the president benefited from his family's foreign business dealings, although they have not yet produced any solid evidence that he did.

In the...