Kansas farmer Glenn Brunkow calls this time of year "go time," when farmers harvest fields and move livestock.

But this harvest season, diesel prices are more than $2.50 per gallon higher than a year ago.

That adds to pressure from rising costs, unpredictable markets and shrinking profits.

Brunkow, president of the Kansas Farm Bureau, said the problems seem to come "from all directions."

The economic strain is a growing political concern for Republicans in states they have long dominated.

President Donald Trump is heading to Kansas on Monday and Iowa later in the week.

He is trying to energize his base in the final weeks before the midterm elections.

Republicans are pouring money into Senate races in Kansas, Nebraska and Iowa amid concerns about voter enthusiasm.

In Kansas, Republican Sen. Roger Marshall faces a tough challenge from Democrat Adam Hamilton.

Democrats have not won a Senate election in Kansas in 94 years.

Brunkow said he is often asked whether economic frustration could push Republican farmers to vote for Democrats.

He said he does not think it does, but it dampens farmers' enthusiasm to get to the polls.

Don Hineman is a western Kansas rancher and former Republican state House majority leader.

He said frustration is growing among GOP voters beyond farmers.

He said farmers understand that Trump's tariffs have hurt their businesses.

Hineman said he is fed up with the Republican Party and is willing to consider alternatives.

Debbie Geneva, 61, of Nortonville, Kansas, said she has never voted for a Democrat.

However, she is undecided about the Senate race.

Diesel averaged $6.30 per gallon nationwide on Friday, more than 70% higher than a year ago, according to AAA.

The USDA projects net farm income will decline by 2.6% this year as production expenses rise by 4.5%.

The Trump administration has tried to ease the burden.

This month, Trump signed an executive order to ease limits on the tax-free use of red-dyed diesel.

That came after a $12 billion aid package for farmers announced in December.

Brunkow said many farmers "thought it would be better" under Trump.

Still, he thinks most would consider him the better choice.