Last year’s GOP primary in Colorado’s 5th district was so dirty that the local Republican Party wants to make sure it doesn’t happen again this time around.

And with the three top contenders from that primary in the race again, the chairman of the El Paso County Republican Party last week issued a stern warning that the GOP would not help anyone who engages in negative attacks.

“Over the years we have seen divisive, dishonest attacks. We will leave those political tactics — and anyone who utilizes them — behind,” El Paso GOP Chairman Gregory Garcia said.

In the conservative district based in Colorado Springs, the challenge isn’t keeping the House seat in GOP hands, but keeping the Republicans from bloodying each other and ensuring that they work together to help candidates up and down the ballot.

“It’s just that kind of district; they’re not going to elect a Democrat,” said Floyd Circuli, an independent, Denver-based pollster.

Rep. Doug Lamborn (R-Colo.) won the general election in November to replace retiring Rep. Joel Hefley (R) by a 19-point margin, but he won the primary by just 900 votes. The second-place finisher in the six-way primary, former Hefley aide and Colorado lobbyist Jeff Crank, announced in August that he would once again run against Lamborn in the primary.

Many Colorado political observers believe that in a one-on-one primary race with Lamborn, Crank would have a better-than-even chance of beating the freshman Congressman. The question is whether Crank will get his wish in 2008.

Last year’s primary was largely a duel between the two Republicans, who battled over taxes and gay rights. Crank claimed that Lamborn’s advertisements, funded in part by the Club for Growth and the Christian Coalition of Colorado, unfairly accused him of having more liberal views on those issues than he actually did.

Lamborn’s campaign last year denied any connection to the disparaging materials that Crank objected to, saying they were aired and distributed without the candidate’s consent.

“We trust this year’s campaigns won’t become like that,” said Kristen Hainen, a spokeswoman for Lamborn’s campaign.

But the bad blood lingers — and the outgoing Congressman, Hefley, refused to endorse Lamborn in the general election.

Hefley was repeatedly quoted as saying Lamborn’s campaign was “sleazy” at the same time he acknowledged that doing so could threaten GOP prospects for holding the gubernatorial and attorney general seats.

Hefley didn’t even rule out voting for the Democratic nominee in the previous cycle, Air Force veteran Jay Fawcett. Lamborn’s campaign decried Hefley’s stance and turned its attacks on Fawcett, calling him “outta control” and a liar and accusing him of trying to sugarcoat his liberal views. Democrats in Colorado and Washington, D.C., relished the division, saying it could help their chances in a district that has never elected a Democrat to the House.

It didn’t. But the division does provide some insight into what could happen down the road in the 5th district and elsewhere in the state, as Colorado continues to become far more hospitable to Democrats.

“At least one reason why [Colorado] is becoming an increasingly fruitful place for Democrats is because of the division [in the GOP], and you’re seeing that played out in the Lamborn race,” Circuli said.

The fault lines in this division are illustrated by the money raised by Crank and Lamborn thus far.

Crank took in $77,000 after just six weeks of campaigning, and it came mostly from Coloradans.

Lamborn raised just a few thousand more, $86,000, in the entire third quarter, and it came mostly from outside groups.

Crank is formally staging a campaign kickoff on Monday at a hotel in Colorado Springs. But before he can focus on Lamborn, he must figure out how to dispatch the third Republican in the race, retired Air Force Maj. Gen. Bentley Rayburn, who finished third in last year’s primary, about 8 points behind Crank.

Rayburn and Crank had been talking for months, as their supporters urged one to defer to the other so Lamborn critics could have a clean shot at the incumbent. But that evidently won’t happen — at least initially.

Even if all three go to the district Republican convention early next summer, it is possible that one of the challengers will drop out before the GOP primary in August.

When he announced earlier this month that he would be running again, Rayburn brought up the feud between Crank and Lamborn, saying he would be “best positioned to reunite this party.”

Some analysts say Lamborn has not done everything possible to retain his seat. And some Republicans wanted more closure after the bitter 2006 campaign.

But Lamborn’s spokeswoman said the reason he has not doggedly worked to reassert himself on the campaign trail is because he is trying to avoid the bitterness of the previous campaign.

“The people of the 5th district went through some rather aggressive campaigning last time around, and I feel it will turn off voters rather than sway their support,” Hainen said.

“Congressman Lamborn wants to run on his record and let the facts speak for themselves.”