Transportation advocates are worried the defeat of House Majority Leader Eric Cantor (R-Va.) on Tuesday could put the brakes on congressional efforts to prevent the federal highway fund from going bankrupt this summer. 

Cantor was unexpectedly defeated in a primary election Tuesday night by Tea Party challenger Dave Brat. The lame-duck majority leader was a leading champion of a Republican proposal to tie transportation funding to cuts at the U.S. Postal Service, raising questions about that plan’s future.

AFL-CIO Transportation Trades Department President Ed Wytkind told The Hill Tuesday that lawmakers should not let Cantor’s defeat halt efforts to find bipartisan compromise on important legislation, in particular on transportation.

{mosads}”If you step away from looking [just] at the Cantor defeat and look at the possible message from last night, this could inject even more toxicity into relations between Democrats and Republicans on the larger issues,” said Wytkind, who has opposed the GOP’s plans for postal cuts. 

“Any long-term solution to the Highway Trust Fund situation is going to have to involve compromise over funding and probably tax reform,” Wytkind continued. “Republicans and Democrats must move on and not let the Cantor election derail a responsible package that funds our surface transportation needs.”

House GOP leaders have said that eliminating Saturday delivery by the Postal Service would provide about $15 billion, which they say would be enough to pay for at least one year of transportation projects. 

The traditional source for transportation funding is revenue that is collected by the federal gas tax, which is currently 18.4 cents per gallon. The tax only brings is about $34 billion per year, however, and the current level of transportation spending that was approved by Congress in 2012 is about $50 billion annually. 

Lawmakers are scrambling to come up with a way to plug the gap before a projected bankruptcy of the fund that budget analysts say could occur as early as August. 

Transportation and postal advocates have objected to the GOP proposal, accusing House Republicans of taking a shortsighted approach that will not fix the larger problems at either the Postal Service or in federal transportation funding.

On the verge of his primary election, Cantor defended the House GOP’s transportation from critics he said were “misguided.” 

“Under current House Rules and under recent practice, a transfer of general funds into the Highway Trust Fund must be offset,” Cantor wrote in a memo GOP House members. 

“Given the limited window for action, we believe it is important that an offset be simple and have the support of the Administration and Congressional Republicans,” he continued.

“The move to eliminate the mandate for full six day postal delivery has been requested by the Obama Administration, the Postal Service, and has been included in the postal reform bill reported by Chairman [Darrell] Issa [R-Calif.] and the Oversight and Government Reform Committee.” 

Democrats in the Senate have pushed back against the House GOP proposal.

The primary author of the Senate’s transportation legislation, Sen. Barbara Boxer (D-Calif.), called the House plan “unworkable” last week. 

The Senate’s chief budget writer, Sen. Patty Murray (D-Wash.), said on Tuesday the GOP proposal was the “wrong way to go.”

Cantor told GOP colleagues earlier this month that he was looking forward “to discussing this with you and clarifying any outstanding questions you may have.”

Lawmakers Wednesday morning, though, questioned whether Cantor’s loss meant that all congressional action would grind to a halt.

“You know, my concern is that a lot of things are going to be dead and pushed to the side,” Rep. Pete King (R-N.Y.) said on MSNBC’s “Morning Joe.”

“I’m concerned that, for instance, the [Sen.] Ted Cruz [R-Texas] supporters, the [Sen.] Rand Paul [R-Ky.] supporters are going to use this as an excuse to basically stop the government from functioning,” King continued.