... about 1986.
What happened in 1986?
Why, the Republicans lost control of the U.S. Senate, which they had held since GOP patron saint Ronald Reagan had swept into office in 1980. How many Senate seats did they lose?
That's right, Ronald Reagan lost the U.S. Senate in the 6th year of his Presidency when the Republicans were ousted from eight Senate seats. The Republicans also lost 5 seats in the Democratic House of Representatives , but the Democrats already controlled 253, so didn't have much room to grow.
Did this end the Republican's national election hopes? Well, not quite, considering in 1988 George Bush Sr. racked up 426 electoral votes in a landslide victory. And while Bush may have lost the presidency four years later, a newly-invigorated Republican party romped in 1994 to take control of Congress, which they would control for a decade.
The Democrats will come back, there's no question about it. That's what a two-party system means. The 2016 Senate map in particular will prove brutal for the Republicans. Mitch McConnell's tenure as majority leader will be brief. The question is and will always be: what will it take to drive Democratic base voters to the polls consistently in the numbers needed to win, even in midterms?