GOP Senate Recruitment Difficulty

At The Washington Post, Amber Phillips notes that the Senate GOP has had difficulty in midterm candidate recruitment.  Rep. Ann Wagner (R-MO) recently opted out of a race against McCaskill.

• In Wisconsin, Rep. Sean P. Duffy (R) decided not to run to challenge Sen. Tammy Baldwin (D). There are at least six possible GOP candidates who could try to challenge Baldwin.In Indiana, Rep. Susan Brooks (R) decided not to run against Sen. Joe Donnelly (D), possibly the most vulnerable Senate Democrat. Her colleagues, GOP Reps. Luke Messer and Todd Rokita, do look like they'll run, and they've already started attacking each other in pretty dramatic ways, like accusing the other of planting negative stories or making “unhinged” comments.
• In Pennsylvania, Rep. Patrick Meehan (R) decided not to run against two-term Sen. Robert P. Casey Jr. (D). Now there are at least four Republicans who have launched campaigns, from state representatives to a real estate developer and an energy executive. Pennsylvania Republicans tell National Journal they'd feel better about the race if either U.S. Reps. Lou Barletta or Mike Kelly decided to run. (Both have said they're thinking about it.)
• In West Virginia, a state Trump won by more than 40 (!) points, U.S. GOP Rep. Evan Jenkins is running to try to unseat Sen. Joe Manchin III (D). But a super PAC recently jumped into the race in favor of likely GOP candidate Attorney General Patrick Morrisey and attacked Jenkins as a Manchin “mini me.”In Ohio, state Treasurer Josh Mandel (R) is the leading candidate to challenge two-term Sen. Sherrod Brown (D). But a wealthy investment banker and GOP donor decided to run, too.
• And Montana Republicans lost their top recruit, Ryan Zinke, after Trump picked him to be his interior secretary. Attorney General Tim Fox (R) also said no thanks to challenging two-term Sen. Jon Tester (D), which has left the state auditor as the biggest name among half a dozen potential candidates.
• Finally, in North Dakota, Republicans don't have a candidate yet to challenge Sen. Heidi Heitkamp (D), another state Trump won by double digits (20 points).