Sen. Gordon Smith (R-Ore.) has hemorrhaged support since midsummer in his tough battle for re-election against state Speaker Jeff Merkley (D), according to a new automated poll conducted for Roll Call and KATU-TV by SurveyUSA.

In a survey of 708 likely voters conducted Monday and Tuesday of this week, Smith was statistically tied with Merkley, trailing the Democrat 44 percent to 42 percent, with 6 percent undecided. Constitution Party candidate Dave Brownlow registered at 8 percent. Back in early August, Smith led Merkley 49 percent to 37 percent in a SurveyUSA poll.

“The contest today is effectively even,” said the polling memo prepared by SurveyUSA, which referred to the race as “difficult to handicap.”

In the presidential race, Sen. Barack Obama (D-Ill.) led Sen. John McCain (R-Ariz.) by 11 points, 52 percent to 41 percent. President Bush’s job-approval rating clocked in at an abysmal 24 percent, with 70 percent disapproving, while an even worse 13 percent approved of Congress’ job performance, with 68 percent disapproving.

The poll’s error margin was 3.8 points.

There appear to be three culprits of Smith’s slide from the 12-point lead he held over Merkley in the Aug. 2-4 SurveyUSA poll: male voters, Obama and Brownlow, the third-party Senate candidate who is running as an anti-abortion-rights, anti-war, libertarian-style conservative.

Brownlow in this poll garnered the same percentage — 8 percent — as he did in early August. He continues to receive a small but significant chunk of support from traditionally Republican constituencies, including 9 percent of men, 10 percent of those 50 and up, 9 percent of whites, 7 percent of registered Republicans and 11 percent of self-described conservatives.

Brownlow also garnered the support of 15 percent of registered independents — a voting bloc long considered by the Smith campaign to be the key to the Senator’s ability to win in a state that has grown increasingly Democratic.

The male vote also looks to be problematic for Smith. In the August poll, Smith led Merkley among men 51 percent to 35 percent. In this week’s poll, Merkley led 47 percent to 40 percent.

Smith’s 48 percent to 39 percent lead among women from the August poll has also dropped, although the incumbent still held a narrow 43 percent to 42 percent lead among women in this week’s poll.

Meanwhile, Obama’s rise has also emerged as a clear advantage for Merkley, who has depended largely on the Democratic Senatorial Campaign Committee to stay competitive and was unknown statewide before this race began. Merkley barely won his Senate primary against Steve Novick, a lawyer who was clearly opposed by the Democratic establishment.

Back in August, Obama’s lead over McCain was small, at 48 percent to 45 percent. In this week’s poll, as Merkley went from 12 points down to 2 points up, Obama saw his lead over McCain increase by 8 points, to 52 percent to 41 percent.

SurveyUSA polls use an automated interviewing system, as opposed to person-to-person interviews. This week’s survey, conducted jointly for Roll Call and Portland television station KATU, occurred amid severe anxiety over the state of the economy and a proposed $700 billion federal bailout for Wall Street.

Across the board, the results of this week’s poll of likely Oregon voters paints an increasingly troubling picture for Smith.

The incumbent Republican garnered the support of 36 percent of independents, compared with 45 percent for Merkley. Smith was backed by 72 percent of self-described conservatives, while his Democratic challenger had the support of 79 percent of self-described liberals.

Regionally, Smith is losing the Portland area to Merkley by 6 points, 46 percent to 40 percent, while winning the rest of the state by just 3 points, 45 percent to 42 percent.

Merkley also is winning among both college graduates and those without a college degree, with his lead over Smith at 44 percent to 42 percent and 44 percent to 41 percent, respectively.

In the favorable ratings, Smith and Merkley were both upside-down. But Smith had higher net negatives than Merkley.

The two-term Senator had a 31 percent/42 percent favorable/unfavorable rating, with 22 percent neutral; the Speaker had a 30 percent/35 percent favorable/unfavorable rating, with 25 percent neutral. Among men, Smith’s negatives were more pronounced, at 31 percent/45 percent favorable/unfavorable. He did better among women, garnering a 31 percent/40 percent favorable/unfavorable ratings.

Merkley ran even with men, with 34 percent favorable and unfavorable ratings. Among women, he ran 26 percent/36 percent.

By far, the issue Oregon voters are most concerned about is the economy, a strong suit for Democrats, particularly because the GOP is the incumbent party in the White House.

Of those polled this week, 51 percent said Congress should focus on the economy ahead of all other issues. Coming in second at 10 percent was health care. The Iraq War, wildly unpopular in the Beaver State, came in third at 7 percent.

Gasoline, as an issue, registered a miniscule 3 percent — a sign that the issue’s potency has faded as the economy overall has dominated the political discussion of the past two weeks.