The Machine Shed restaurant, where the waitresses wear bib overalls and suggest a cinnamon roll the size of a loaf of bread as a breakfast appetizer, sells a root beer called Dang!, bandages made to look like bacon strips, and signs that proclaim “I love you more than bacon.” For Joni Ernst, however, the apposite sign reads “No one ever injured their eyesight by looking on the bright side.”

She, nourished by a cinnamon roll, is preparing for a bus tour taking her Senate candidacy to all of Iowa’s 99 counties, and she seems to love campaigning even more than bacon, not that any proper Iowa farm girl – her description of herself – would publicly rank bacon second to anything. Ernst, a 44-year-old state senator, or Bruce Braley, a 56-year-old four-term Democratic congressman, will replace Sen. Tom Harkin, who is retiring after five terms. Of the five Senate contests in purple states – Iowa, Virginia, North Carolina, New Hampshire, Colorado – this is currently the closest: The Real Clear Politics average of polls shows a tie (Ernst ahead by 0.2 percentage points).

Which should make Republicans anxious as they try to take control of the Senate and as they contemplate the 2016 presidential landscape. Although Iowa has voted Democratic in six of the last seven presidential elections, the Ernst-Braley contest should not be this close.

Only 38 percent of Iowans approve of Barack Obama’s performance. Braley, a past president of an Iowa trial lawyers association, is as awkward as Ernst is ebullient when campaigning. And the Democratic Party’s single idea – the trope that Republicans live to wage a “war on women” – leaves Ernst bemused: “I am a woman and I have been to war and this is not war.” A 5-foot-2 grandmother, she is a National Guard lieutenant colonel who served in Iraq.

Although outspent by her chief opponent 10-to-1 in the first quarter of this year, she won a five-candidate primary with 54 percent of the vote, propelled by an ad in which she said that having grown up castrating pigs, she would be able to cut Washington spending. She does, however, genuflect at the altar of Iowa’s established religion, the Church of Ethanol, a federally mandated Iowa sacrament made from corn.

The Ernst of the primary season talked about the Harley in her driveway, the pistol in her purse, and the possibility of impeaching the president. Today her less exotic persona talks about the feeble economy, the perils of Obamacare, and Braley’s record, including his pride in having given in the House the culminating argument for Obamacare, which he still thinks is splendid.

Then there is his interesting path to his current position on the Keystone XL pipeline, which he favored before he opposed it. In 2012 he voted for construction, and for removing the requirement that the president approve construction. He now opposes Keystone, which makes his position conveniently congruent with that of Tom Steyer, the billionaire who is dispersing millions of dollars to support candidates who share his opposition to Keystone. Steyer’s NextGen Climate super PAC has spent $2.6 million attacking Ernst. Politics is an inherently transactional business but Braley’s fretting about money in politics – he is operatically indignant about the Koch brothers – is notably selective. So far, Ernst’s campaign and independent groups advocating on her behalf have spent about $2 million less on ads than Braley’s campaign and supporting groups have spent.

Gov. Terry Branstad, a Republican who served four terms 1983-1999, is now in his fifth and has a double-digit lead in his quest for a sixth, and is already the longest-serving governor since colonial times. His coattails should help Ernst in the voting, which began last Thursday. Ernst is also warmly supported by Iowa’s six-term Sen. Charles Grassley, who would be chairman of the Judiciary Committee in a Republican-controlled Senate. Braley, speaking at a fundraiser to other trial lawyers in Texas, and evidently forgetting that nowadays cellphones are also video cameras, was recorded lamenting that Republican control could put Judiciary’s gavel in the hands of “a farmer from Iowa who never went to law school.” And Braley, this year’s leader in unfortunate ad libs, probably should not have shared with voters the misery he experienced last autumn when, because of the government shutdown, there were no fresh towels in the House gym.

Iowa is one of two states – hello, Mississippi – that have never elected a woman to a federal office or governorship. In other circumstances, might Braley consider this, too, evidence of a war on women?

© 2014, Washington Post Writers Group