Since the next Bachelor is usually picked from the previous season of The Bachelorette's final four, we know who the options are, barring some late-breaking curveball. The next lead is going to be Bryan, Dean, Eric or Peter.
But even within those four there are more and less likely candidates. Plus one of them is currently engaged to Rachel, so he's out, whoever he is (probably Bryan).
The bottom two contenders would appear to be Dean and Eric. They just don't seem ready for the job. Dean is immature — there's something Bieberish about him — and Eric is too emotional. We saw him fly off the handle earlier in the season at Lee. He was justified, because Lee is the worst, but you can't have a Bachelor who'll lose his temper on TV. Plus he's been very in his head over his relationship with Rachel. He just seems on some basic level too sensitive to handle being the Bachelor.
That leaves Peter and Bryan. Bryan will last longer on The Bachelorette than Dean or Eric, but he somehow seems less likely to be the Bachelor than either of them. This is for two reasons: one, there's a very good chance that he's the one Rachel chooses at the end (she's very, very into him) and two, no one in the world likes him as much as Rachel and his mother do. People just aren't really feeling him.
And popularity can be quantified. Social media followings are not a deciding factor in choosing the next lead, but they are taken into account. Here are their Instagram follower counts, as of Monday, July 24, before the episode airs: Dean in the lead with 377K, Peter in second with 251K, Bryan in third with 134K and Eric in last place with just 37.5K. So yeah, it won't be Eric.
But anyway, cast your vote! Results will be announced later this week.