No----no they(national polls) weren't. Rasmussen was the most accurate but did not get it fully right either. ---Betting odds are a much better way of forecasting outcomes than polls are----and are much more up to date as well.
Oddsmakers had Hillary- 500 National Polls showed Hillary would get more votes and she got millions more votes
Reader----the 2018 midterms were the 5th best in US history for the party in power in The White House. Dems had more votes simply because most of the Senate races were in states that had Dem incumbents up for reelection. It's a simple as that.