The primary factor

Speaker John BoehnerJohn BoehnerTrump aide: Boehner is the disaster Boehner: Tax reform is 'just a bunch of happy talk' Lobbying World MORE (R-Ohio) recently has had a tough time passing high-profile bills, including a payroll tax extension late last year and a five-year, $260 billion transportation measure this month. 

He bowed to the Senate on the payroll tax bill and has punted highway legislation down the road. On Tuesday, the House debated a 60-day stopgap bill that would extend funding for federal highway programs. A scheduled vote on the measure was scrapped, however, because it lacked the votes to pass under suspension rules, which requires a two-thirds majority. 

Democrats have cried foul, claiming a two-year, $109 billion bipartisan transportation bill that passed the Senate should be sent to President Obama’s desk. Obama last weekend in his radio address called on the House GOP to send him the Senate’s bill. 

During Tuesday’s deliberations on the House floor, Democrats asked why Republicans want to delay. They note that BoehnerJohn BoehnerTrump aide: Boehner is the disaster Boehner: Tax reform is 'just a bunch of happy talk' Lobbying World MORE doesn’t have the votes now for his five-year bill and say he won’t have them later, either.

That prediction might come true, but there is one notable difference between the end of March and the end of May: Many primaries take place between now and then.

Republican lawmakers facing primary challenges don’t want to vote for a big-spending highway bill weeks before their constituents go to the polls. That vote could be used against them, regardless of the fact that the bill is paid for. 

Boehner also wants to pass Rep. Paul RyanPaul RyanFive goals for Republicans this summer Five tax reform issues dividing Republicans GOP leader tempers ObamaCare expectations MORE’s (R-Wis.) budget resolution this week. Last year, only four House Republicans rejected his scheme. This year, there will be more. Why? Some conservatives claim it doesn’t cut enough. 

But Ryan says he has the votes to get his measure through the lower chamber, and he is probably right. Still, the fact that the debate comes during primary season doesn’t help GOP leaders.

There are 87 freshmen in the GOP class. Most don’t have challenging primaries, but about a quarter do. Moreover, there are pending member-vs.-member matchups this year due to redistricting.

That’s all bad news for Boehner and Majority Whip Kevin McCarthy (R-

Calif.), whose job is to round up votes.

The good news for the House GOP, however, is that party unity might be less elusive later this year after primary season concludes. Many of those 87 freshmen have to worry about Democratic challengers in November, but in some ways that’s a more manageable problem.