Today, Republicans will decide key Senate primaries in two crucial states; Indiana and West Virginia.  Both states are represented by vulnerable red-state Democrats and Republicans are increasingly anxious the results of the primaries could determine the fate of their Senate majority in November.

Both primaries have been contentious.  In Indiana, a slugfest between Congressmen Luke Messer and Todd Rokita has been complicated by self-funding businessman Mike Braun.  In West Virginia, the same dynamic is at play with Congressman Evan Jenkins and state Attorney General Patrick Morrisey’s battle be blindsided by the surprising success of former coal baron and convicted felon Don Blankenship.

In West Virginia, Blankenship’s rise has concerned Republicans the most.  The former coal baron was convicted of criminal negligence following the 2010 explosion at his Upper Big Branch Mine where 29 workers were killed.  Polling of the race has been sparse but has shown Blankenship tied or near parity with his more mainstream rivals.  Republicans have been so concerned they have gone on air against Blankenship and Donald Trump tweeted to his supporters not to support Blankenship.

Many Republicans worry while Blankenship appeals to the anti-establishment wing of the GOP he will struggle to connect with suburban Republicans in the Northeastern corner of the state and turn off Independents.  Worse, Manchin likely will contrast his support for and successful passage of a bill that protected former coal workers health insurance with that of Blankenship’s conviction.

Both Jenkins and Morrisey are more conventional candidates in the sense they are traditional conservatives but have a populist appeal that plays well to West Virginia.  Owing to the recent swing of West Virginia to Republicans at the local level, Jenkins has been attacked for being a former Democratic State Representative until 2014 when he ran as a Republican for Congress.  He defeated 18 term Democratic Congressman Nick Rahall that year.

Much like Jenkins, Morrisey defeated a long-time incumbent to inhabit his current post.  In 2012, he defeated the 5 term Democratic Attorney General.  Morrisey was easily reelected in 2016.

Based on their history, Republicans feel confident Morrisey or Jenkins have what it takes to defeat a Democrat with local roots in a red state.  Not so much Blankenship.

In Indiana, the GOP primary to take on Joe Donnelly has turned decidedly nasty.  Messer and Rokita have hammered each other with ads and their personal dislike of each other is well known.  As other better known candidates have done in the past, their hammering of each other has allowed a businessman outsider, Mike Braun, to come up through the middle.

Only lately have they turned their fire on Braun.  National Republicans have not picked a horse in this race but recently it came out Braun had voted in Democratic primaries since 2012 and the company he runs has been flagged for dozens of safety violations since 2015.  Whether these late breaking stories damage his momentum remains to be seen as few surveys of the race have been taken.

Republicans are hoping for good news tonight, especially out of West Virginia, as they have supposedly learned from the mistakes of 2010 and 2012.  That year, Republicans allowed a number of problematic nominees to make it out of Senate primaries due to their lack of involvement.  In 2014, Republicans shepherded their best nominees to the general where they mainly succeeded in marquee races.

Republicans have heavily used this strategy in West Virginia by having an allied Super PAC attack Blankenship.  Trump’s late entrance into the race also seems to indicate even the President understands his agenda is in danger if Democrats gain the majority or maintain their current numbers in the Senate.

Of course, the results of one primary do not necessarily mean Republicans are doomed if they blow, say, a West Virginia.  But, it becomes harder as Republicans waste an opportunity.  Plus, there is an increasing worry among Republicans John McCain may retire or pass away before November.  If so, a special election would need to be held to finish out his term.

Right now, conservative outsider Kelli Ward, firebrand former Maricopa Sheriff Joe Arpaio and Congresswoman Martha McSally are running for Jeff Flake’s open seat.  But, if McCain passed away or stepped down, Republicans worry either Ward or Arpaio would switch races and all but ensure Democrats would take the seat (this assumes Democrats would not have a similar ideological problem on their end).

Fortunately, Republicans seem to have gotten their preferred nominees in North Dakota and Missouri without messy primaries.  Plus, Governor Rick Scott has taken the plunge in Florida.  And, as much a reach as Ohio is, there is little risk Rep. Jim Renacci does not make it past the primary even facing a self-funding businessman.

Still, it is not surprising so many Republicans are worried about the results of West Virginia tonight.  One of their bast targets this cycle might slip through their fingers and that has them rightly worried.