– Further evidence of the never-ending federal election cycle is cropping up in western Minnesota.

In its first targeted campaign of the season, the National Republican Congressional Committee, the campaign arm of House Republicans, aired televised attack ads this month against Rep. Collin Peterson, D-Minn. — more than 18 months before voters go to the polls.

The ads attempted to tie Peterson to President Obama and his health care reform law, the Affordable Care Act, both unpopular in his sprawling rural district. "Instead of voting to balance the budget, he voted to spend $1.8 trillion on Obamacare," a narrator said in the ad.

Peterson did not vote for the Affordable Care Act, but voted against its repeal. He also voted against the House Republican budget, which brings federal spending in line with revenues over 10 years.

Peterson laughed off the attack. "They don't have anybody else to go after," he said. "It's kind of ridiculous, but whatever."

The Seventh District is a political anomaly, a conservative-leaning district represented for almost a quarter-century by a Democrat.

On the surface, it makes sense to challenge Peterson there. According to the Cook Political Report's Partisan Voting Index, Peterson has Minnesota's second-most GOP-leaning congressional district, trailing only that of Rep. Michele Bachmann. Nationally, Peterson is in the fifth-most Republican-leaning district represented by a Democrat.

"The DNA of the district is very competitive. It's one that should be in play every election when you look at the underlying mechanics," said Jessica Taylor, an analyst with the Rothenberg Political Report.

But the numbers and rhetoric haven't added up for Republicans in almost two decades. That was the last time an election challenger came within 10 percentage points of Peterson. In 2012, Peterson captured 60 percent of the vote, defeating his opponent by 26 percentage points.

"He's built a brand for himself in the district," said Brandon Lorenz, a spokesman with the Democratic Congressional Campaign Committee.

So far, Republicans have not found a viable candidate to challenge Peterson in 2014.

"Every day I run into people who tell me, 'You're the only Democrat I've ever voted for and I vote for you every time,' " said Peterson, the lead Democrat on the House Agriculture Committee.

On Tuesday, the National Republican Congressional Committee released an analysis of Peterson's first-quarter campaign fundraising that shows that almost 90 percent of his donations came from outside Minnesota; of the 62 individual donors, seven are from Minnesota.

"Money talks," said Alleigh Marre, an NRCC spokeswoman. "And it's evident that Minnesota families don't think they're getting their money's worth from Democrat Collin Peterson."

Veteran representatives from both parties, especially those who serve as committee chairs or ranking members, often receive a sizable portion of their donations from political action committees. In the last election cycle, roughly 80 percent of Peterson's donations came from PACs.

A $2,000 ad buy

As a conservative Democrat, Peterson's votes are scrutinized by allies and critics, because his decisions often are not governed by party allegiance. Peterson's district is one of seven in the country still held by a Democrat whose constituents voted for the Republican nominee in each of the last three presidential elections.

"Collin has to be careful in this district, careful in what he says, careful in how he votes," said Craig Bishop, chairman of the state's Seventh District Republican Party.

The NRCC spent $2,000 on the early ad campaign against Peterson, which is a paltry sum, said John Geer, a political scientist at Vanderbilt University in Nashville, Tenn. "It's just not that much money."

The committee has spent six times as much on ads for other Democratic targets.

Meanwhile, the release announcing the Peterson ads was not personalized. After chiding Peterson for expecting "Minnesota seniors to foot the bill for his unbalanced, irresponsible priorities," the statement from communications director Andrea Bozek read: "Peterson owes Utah families an explanation for his poor record, and his support of wildly expensive law that hurts jobs and Utah's seniors."

Political committees on both sides often run the same ads in various states, changing only the candidates' names.

Missteps aside, Republicans say that Peterson has lost touch with his district and that a strong candidate could test his mettle and voting record in 2014.

"We are committed to supporting a candidate that best reflects the views of Minnesota's Seventh District," Marre said.

'Shots across the bow'

This early in the election cycle, the NRCC ad buy may signal to potential Republican candidates that they're prepared to "fire a few shots across the bow" and devote more resources in a bid to unseat Peterson, Geer said.

"I bet the candidates running against that incumbent haven't been that good," he said. "If you can give the Republicans a reason to vote for one of their own, they will."

During the past eight elections, Peterson has faced a string of challengers with limited political experience. Among them, former state Sen. Dan Stevens was the only candidate who had served in the Legislature. Peterson trounced him by 30 percentage points in 2002.

In each of the last two elections, Peterson soundly defeated businessman Lee Byberg by more than 20 percentage points.

Byberg has not announced plans for a third run at Peterson's seat. Bishop, the district GOP chairman, said former state House candidate Scott Van Binsbergen of Montevideo formed an exploratory committee for 2014, but has not committed to challenging Peterson.

With no candidate in place, national Democrats have not blinked at the latest threat from Republicans. Of the seven Democrats targeted, five are in the DCCC's Frontline Program, an effort led by Rep. Tim Walz, D-Minn., to protect incumbents in politically vulnerable House seats. Peterson, a capable fundraiser with deep ties in the agriculture industry, has not been asked to join the program.

"[Republicans] haven't done a thing," Peterson said. "They're going to have a hard time getting any traction."

Corey Mitchell is a correspondent in the Star Tribune Washington Bureau. Twitter: @C_C_Mitchell