I know that the Republicans would much rather keep control of at least the Senate, and ideally keep the House too, but they should not be shocked or dismayed if they lose one or both. For many decades now, it has often happened that the party in the White House has lost many seats in Congress in the mid-terms, and on several occasions has lost control of the House and/or the Senate. It happened under Eisenhower, Reagan, Clinton, Bush, and Obama.
So it would not be a shocking new event, much less the end of the world, if the Dems were to take control of one or both chambers of Congress, since they would not have anything close to a veto-proof majority in either chamber, which would mean that Trump could veto anything he didn't like and the Dems could not override his veto.
So it would not be a shocking new event, much less the end of the world, if the Dems were to take control of one or both chambers of Congress, since they would not have anything close to a veto-proof majority in either chamber, which would mean that Trump could veto anything he didn't like and the Dems could not override his veto.