1. How many total Republicans in Congress have already announced that they will not run for reelection in 2018?
12 House Republicans and 2 Senators
2. How many total Democrats in Congress have already announced that they will not run for reelection in 2018?
3 House Democrats and no Democratic senators
3. What is so unique about the discrepancy between these two groups?
All of the Democratic senators are running for reelection and only 3 Dem. House members are retiring.
4. What factors do the authors of the article suggest are behind these decisions not to run for reelection?
Republicans are afraid of a backlash against their party because of Trump's low ratings and the sweeping wave of Democratic victories.
5. Why might the elections for those in "safe red districts" be more difficult than in recent elections?
Most retirees explained their decision with term limits for committee chairmanships or old age. Also, many don't want to stay because they think their party will fall into the minority or are unwilling to face a grueling race.
6. Why does the large number of incumbents retiring make it easier for Democrats to gain seats in the House than they otherwise would?
Since many Republicans are retiring, it opens more seats for Democrats to run their candidates.
7. Why might this same thing help Democrats recruit better candidates?
Potentially strong candidates are often more willing to run in an open-seat contest than take on an incumbent.
8. About how much does FairVote say that incumbents are helped just by being incumbents in a normal election year?
The incumbency advantage has been between 3-7%.