First he said he wouldn’t, he explained why he’d refuse, then he said he would.
From the Republican’s point of view it would make more sense to subpoena Hunter Biden than Joe Biden because as Chuck Schumer said Hunter Biden Testifying Would Make Impeachment Trial A ‘Circus’ which is what the GOP wants. But then Hunter Biden isn’t well known except by name. Joe Biden is the star and he is Trump’s current main competitor.
There are many benefits to having one or both of them testify. The obvious one is that there is no there there. Their testimony will deflate Trump’s rationale for claiming he was justified in pushing for the investigation into corruption in Ukraine involving Burisma and the Bidens.
Another benefit is that it backs Mitch McConnell into a corner if he refuses to allow the Democrats to call their witnesses. I would expect Joe Biden and the Democrats to raise holy Hell if he and/or Hunter testify. This demand will gain more traction what with the breaking news:
Whether Schumer cuts a deal in advance, I hate to say it, a quid pro quo, with McConnell and says he’ll trade witnesses two for two and selects the two most important witnesses may not matter. It would be difficult to choose the two most advantageous witnesses for the Democrats. The higher profile the better so I’d say it’s between Bolton, Pompeo, and Mulvaney, probably the first two depending on what it is anticipated Mulvaney (the less famous) would have to say.
We see what happened when highly credible yet unknown witnesses testified in the impeachment trial. We need well known faces and Bolton and Pompeo certainly qualify. I doubt Bolton would lie to protect Trump. Pompeo is another story, but would he lie knowing that he could end up in prison for perjury? He’s in a tough spot since although he denies wanting to run for the Senate in Kansas he may want to hedge his bets for Trump losing the election, but going against Trump might not sit well with Trump’s base in Kansas.
Without a quid quo pro agreement in advance, if one or both Bidens testify there would be strong public pressure on the GOP to allow at least as many witnesses of called by Democrats. If they had only one I suspect it would be John Bolton because he has already said he was against withholding the aide to Ukraine and thought it was like a drug deal.
Perhaps the biggest benefit to having the Bidens testify is that this would be must-see television viewing for Fox News addicts hoping to see their Republican heroes eviscerate them. Keeping in mind that this is a trail and that while the Republicans acting as defense attorneys will be able to question the Bidens the Democrats acting as prosecutors (don't forget, they are prosecuting the president) will also question them.
Not only will the testimony be nothing more than a lackluster lead-in act for the main show when the Democrats call their witness but it will provide Joe Biden with a chance to cement his lead in the polls if he comes across as presidential.
Undecided Democrats will be watching closely to see how Biden handles the hostile questioning from someone like Jim Jordan, and I hope the GOP will choose this screeching former college wrestling coach and graduate of Capital Law School which is rated 193 in the U.S. No matter who questions him, one good comeback line could be the memorable meme that gets Biden the nomination and the presidency.