The one question likely to decide 2018 elections

As the 2018 election year begins, one question above all is likely to shape its outcome: Will Americans vote to constrain President Donald Trump by electing a Democrat-led Congress that will challenge and resist him, or to empower the Republicans who are increasingly working in harness with him?

Voters have increasingly viewed House and Senate elections less as a choice between individual candidates than a referendum on which party they want to control Congress — a choice grounded in their assessments of the President. All evidence from the special elections in 2017 suggests that pattern will continue to drive voters’ decisions this year. CONT.

Ronald Brownstein, CNN