The disaster looming for House Republicans on Election Day is nowhere more apparent than in Arizona’s conservative 3rd district, where Rep. John Shadegg (R) finds himself embroiled in a tough race despite hometown Sen. John McCain’s position at the top of the Republican ticket.

Shadegg is facing a determined challenge from attorney Bob Lord (D), who is well-funded and running a strong race compared to what some Republicans say is a lackluster campaign by the incumbent.

Still, Lord is hardly the kind of big-name conservative Democrat ordinarily considered capable of putting an incumbent like Shadegg on the defensive — particularly in a presidential year. But an already-tough political environment has only gotten worse for Republicans since mid-September.

Under the weight of a fundraising disadvantage that has allowed the Democratic Congressional Campaign Committee to spend $675,000 against Shadegg unchallenged, his situation is emblematic of the peril facing House GOP incumbents in several seemingly safe districts.

“Shadegg is looking at his race and realizing he could lose,” said a Republican consultant based in Arizona.

Privately, Republican operatives are critical of Shadegg’s campaign, saying the Congressman has not adequately responded to what they say are unfair and inaccurate Democratic attacks by the Lord campaign and the DCCC — although the Arizona Republican operative expects the Shadegg campaign to take corrective measures by week’s end.

The National Republican Congressional Committee — providing the counterattack that Shadegg presumably has not — is pushing back, if only rhetorically, against the Democratic critiques, which have centered on claims that the Congressman has become a creature of Washington who puts party ahead of the interests of his district, state and country.

“Even when it meant taking on his own party, John Shadegg has never stopped working to bring about reform in Congress,” NRCC spokesman Ken Spain said. “Bob Lord and the DCCC’s attacks are ringing hollow.”

The Shadegg campaign denies that its strategy is to blame for Lord’s rise. Shadegg campaign spokesman Sean Noble blamed the competitiveness of the race on false ads being run by the DCCC, while declining to comment on the dissatisfaction with the campaign’s strategy that has been expressed by some Republicans.

“Campaigns are about timing,” Noble said. “We’re running the campaign by the book. So they’ll see our strategy when it happens.”

Whether Lord’s gains can be attributed to Shadegg’s campaign strategy, the disastrous GOP political environment, or both, the DCCC’s ability to spend heavily in the 3rd district and the inability of the NRCC to respond are at least partially responsible for the Congressman’s vulnerability.

The DCCC on Tuesday filed another independent expenditure report regarding its activities in the 3rd district. Listed were another $18,000 in direct-mail services and $270,000 for a media buy, according to the Federal Election Commission’s Web site. The DCCC has dropped three mailers in the 3rd district, all seeking to portray Shadegg as corrupt and out of touch.

The NRCC had not spent any money in the race as of Tuesday.

Given the strong conservative lean of the 3rd district and with Democrats targeting 50 Republican-held seats in the Nov. 4 elections, the NRCC’s ability to spend money in the 3rd district remains in question. As of Aug. 31, the DCCC reported $54 million in cash on hand; the NRCC had banked just $14.4 million.

The Lord campaign has hit Shadegg for his votes on health care and veterans issues.

But recognizing that the 3rd district remains a Republican bastion, the Democrat is running largely on leadership and style, attempting to capitalize on the poor opinion voters have of Washington, D.C., by casting Shadegg as an unreasonable partisan more beholden to the House GOP leadership than to his constituents.

Lord is campaigning as a centrist.

He has waged a vigorous campaign for over a year; has made no major tactical errors; and had raised more than $1.1 million for the cycle as of Aug. 13, with $658,000 in cash on hand. But Shadegg at the same point in mid-August had raised nearly $2 million for the cycle, reporting $1.4 million on hand, and until a few weeks ago had appeared safely out of Lord’s reach.

“We’re running against a longtime Congressman who’s got a lot of money and a lot of support, so this is always going to be an uphill battle. But I think we’re moving in the right direction,” Lord campaign manager Andrew Eldredge-Martin said. “We’re being aggressive.”

The suburban Phoenix 3rd district leans conservative. Shadegg announced early this year that he was going to retire after seven terms, but he changed his mind after his House GOP colleagues spent a week pleading with him to reconsider.

Last month, after the financial crisis hit in earnest, the weeks of unanswered attacks on Shadegg by the Lord campaign and the DCCC began to have an effect, say political operatives on both sides of the aisle who have been monitoring this race.

One well-placed Arizona Democrat, conceding that the 3rd district is not an easy seat for Democrats to win, echoed what many Republicans have been saying privately, that Shadegg’s weak campaign has given Lord traction in this race.

“Shadegg has absolutely been asleep at the wheel. He considered Bob Lord’s candidacy a joke from the get-go,” this Democratic insider said.