I would be curious to see a timeline where Trump managed to win the popular vote in 2016, therefore giving his presidency more of a 'mandate' right away
The Democrats wouldn't have been any more supportive of Trump's agenda, and Republicans already acted like they had a huge mandate. Perhaps the Russia investigation would be less significant if the election wasn't as close, but even then it was considered something worth focusing on by a lot of people (and imo it was a legitimate concern). The most interesting part of this scenario would be down-ballot ramifications, and if the Republicans had 1 or 2 more Senate seats the healthcare debate may have gone very differently.