President A also lost 6 senate seats along with the 63 house seats. Voters were angry with both the Democratic congress and the president for not listening to their wants and wishes when it came to the ACA. America as a whole at that time was against this legislation by an average of 55-35. 2010 was a rebuke of Obama's policies. Still Obama was liked by most Americans as a man. Independents voted 57-41 against the Democratic House candidates, America as a whole voted 52-45 against Democrats in the house. Obama went on to win reelection in 2012 because of his likability. Independents barely voted Republican in the house elections 50-49.
President B, has lost at the present 30 house seats with 13 more to be decided. Both lost the house which their party controlled. This 2018 election in my opinion wasn't so much about policy which the voters were angry at, it was all about Trump's obnoxious personality and his very unpresidential behavior. Independents are split on his policies, for some, against some. I don't have how independents voted in the house elections this year, but the overall congressional vote went to the Democrats 51.3% to 47.0% for the Republicans. This is with 13 districts pending. In 2016 Republicans won the overall vote 49.1% to 48.0%. A swing of around 3 points overall which resulted in the massive shift in House numbers and the Democrats gaining control. I'm sure independents went Democratic this time, by how much, we'll have to wait on more exit polls with the party breakdown.
I think 2010 was an election which rejected a single policy which remained as an albatross around the Democrats neck for the remainder of Obama. I think 2018 was rejection of Trump's persona, not necessarily his policies. Certainly not legislation since he has only one main success, his tax cuts. I also think Trump will remain an albatross around the GOP necks for however long he is president. Unlike Obama who recovered nicely for 2012 mainly because he was likable, Trump isn't. Being likable by America as a whole gets ignored. But being likable got Reagan past Iran-Contra and got Bill Clinton past his bimbo eruptions. Being disliked, when trouble occurs, the results may be more along the Nixon lines. He wasn't all that likable as a person either.