This story was originally published on nationaljournal.com on May 11, 2017

It’s time for con­gres­sion­al Re­pub­lic­ans and their strategists to start pop­ping their blood-pres­sure meds. Even be­fore Pres­id­ent Trump fired FBI Dir­ect­or James Comey, the po­ten­tial for GOP prob­lems in next year’s midterm elec­tions were real. Ob­vi­ously no one knows what will hap­pen in an elec­tion al­most 18 months away. But now is when in­cum­bents start de­cid­ing wheth­er they will run again. From a party per­spect­ive, it’s al­ways easi­er to de­fend an in­cum­bent’s seat than win an open one.

It’s also the time when chal­lengers and open-seat can­did­ates start mak­ing de­cisions. Sev­er­al of the strongest po­ten­tial Re­pub­lic­an chal­lengers to vul­ner­able Demo­crat­ic sen­at­ors ex­pressed con­cerns to me about the polit­ic­al en­vir­on­ment next year—and that was be­fore Trump’s con­tro­ver­sial dis­missal of Comey.

The Re­pub­lic­an ma­jor­ity in the Sen­ate is not much in danger be­cause Demo­crats are de­fend­ing 25 seats in 2018, 10 of which are in states that Trump car­ried last year, to just nine for the GOP. Even so, the dif­fer­ence between a level play­ing field for Re­pub­lic­ans and one with stiff head­winds is the dif­fer­ence between gain­ing three to five seats versus just break­ing even or per­haps suf­fer­ing the loss of a seat. So it’s a big deal wheth­er Re­pub­lic­ans come out of 2018 with as many as 57 Sen­ate seats, or just stay at 52, or even drop to 51.

But it’s the House that’s on the knife’s edge. Midterm-elec­tion his­tory, com­bined with Trump’s dis­mal job-ap­prov­al rat­ings, already put the House in play. The Comey fir­ing ad­ded to Re­pub­lic­an miser­ies, and but­tressed the Demo­crat­ic Party’s ar­gu­ment that at least one cham­ber of Con­gress should be taken out of Re­pub­lic­an hands in or­der to keep Trump in check. But more than that, the fir­ing is enough to make quite a few Re­pub­lic­ans wince—not a good thing when the mood in the GOP already seemed down­beat. The fir­ing also lif­ted the already high en­thu­si­asm of Demo­crats.

Many polit­ic­al ana­lysts were fo­cused on the spe­cial-elec­tion run­off on June 20 in Geor­gia’s 6th Con­gres­sion­al Dis­trict, to fill the seat pre­vi­ously held by Health and Hu­man Ser­vices Sec­ret­ary Tom Price. Han­di­cap­pers were call­ing that con­test a toss-up be­fore the Comey mess.

An earli­er spe­cial elec­tion, on May 25, to re­place In­teri­or Sec­ret­ary Ry­an Zinke in Montana’s at-large seat, is in­creas­ingly be­ing seen as an­oth­er ca­nary in the coal mine. While Trump car­ried the Big Sky State by 21 points last year, Re­pub­lic­an nom­in­ee Greg Gi­an­forte was lead­ing Demo­crat Rob Quist by just 8 points, 45 to 37 per­cent, in an in­de­pend­ent sur­vey by Grav­is Mar­ket­ing and by 6 points in a sur­vey by one of the top Demo­crat­ic polling firms, Gar­in-Hart-Yang Re­search. The Grav­is poll was taken in the first week of May, and the Gar­in-Hart-Yang poll was con­duc­ted April 25-27. The Demo­crat­ic poll’s re­spond­ents said they voted for Trump by 22 points, mar­gin­ally bet­ter than the ac­tu­al vote in Montana last year. Among re­spond­ents most in­ter­ested in the race, Gi­an­forte’s lead was just 1 point, 48 to 47 per­cent.

I re­main some­what skep­tic­al about the Demo­crats’ chances in Montana. The path to a Demo­crat­ic ma­jor­ity is more likely to go through up­scale, urb­an, and sub­urb­an dis­tricts than rur­al dis­tricts with large white pop­u­la­tions. But if the Montana vote is close, it will send tremors through a lot of Re­pub­lic­an mem­bers who may not have felt vul­ner­able.

It is cer­tainly a pres­id­en­tial prerog­at­ive to fire an FBI dir­ect­or, but this is more com­plic­ated than that. My view is that at every point in the FBI’s in­vest­ig­a­tion of Hil­lary Clin­ton’s email use, Comey did what he thought was right. He ac­ted with the best of in­ten­tions, and did what he thought was in the best in­terest of pre­serving the in­teg­rity of his agency, even though in hind­sight these de­cisions turned out to be mis­takes.

His ac­tions in the clos­ing weeks of the cam­paign made the elec­tion al­most ex­clus­ively about Clin­ton and ul­ti­mately helped de­term­ine the out­come of the elec­tion, though there were cer­tainly plenty of oth­er factors that were im­port­ant as well. Ar­gu­ably an FBI or Justice De­part­ment in­spect­or gen­er­al might have re­com­men­ded that Comey be dis­missed, but giv­en the ex­pand­ing nature of the bur­eau’s in­vest­ig­a­tion in­to Rus­sia’s med­dling in last year’s elec­tion, Trump’s fir­ing of Comey was a huge mis­take, both in terms of policy and polit­ics. It was a rash act en­tirely con­sist­ent with the worst fears that many had about a Trump pres­id­ency, and it cer­tainly will not help his party next year.

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