State Speaker Jeff Merkley (D) is close to launching an exploratory committee for a prospective 2008 Senate bid, and Democrats believe he could pose a formidable challenge to Sen. Gordon Smith (R).

According to The Associated Press, Merkley has met with several Democratic Senators to discuss running, including Sens. Claire McCaskill (Mo.), Sheldon Whitehouse (R.I.), Sherrod Brown (Ohio) and Amy Klobuchar (Minn.).

The Democratic Senatorial Campaign Committee has been searching for a high-profile challenger to Smith since the beginning of the year. Eleven-term veteran Rep. Peter DeFazio (D) told the committee “no” early on, as did state Treasurer Randall Edwards (D).

Merkley, who led a Democratic takeover of the Oregon House of Representatives last year, is said by sources to be the type of candidate the Democrats have been looking for.

Presently, attorney and longtime Democratic policy adviser Steve Novick remains the only Democrat to have launched a campaign against Smith, who is deemed potentially vulnerable because of Oregon’s Democratic tilt and the continuing unpopularity of the Iraq War.

Ousting Smith is among the DSCC’s top 2008 priorities.

— David M. Drucker