National Republican Senatorial Committee Chairman John Cornyn on Friday warned that Democrats should not expect a cakewalk in the upcoming West Virginia special election to replace the late Sen. Robert Byrd (D).

The comment came just hours after Gov. Joe Manchin (D) appointed a placeholder ahead of what is widely expected to be his own campaign for the Senate.

Cornyn acknowledged in an interview taped for C-SPAN’s “Newsmakers” program Friday afternoon that his committee has already reached out to multiple potential GOP candidates, including Rep. Shelley Moore Capito, the lone Republican in the state’s Congressional delegation, and wealthy businessman John Raese, who unsuccessfully challenged Byrd in 2006.

“I think we’ll have a competitive candidate,” Cornyn said.

A special session of the state Legislature that began Thursday is expected to authorize a special election in November to fill the final two years of Byrd’s unexpired ninth term.

Despite the fact that most observes view Manchin — who polls show to be widely popular across party lines — as the prohibitive favorite in that race, Cornyn said the West Virginia special election presents a “great opportunity” in what is already expected to be a very good year for Republicans nationally.

“Even though the governor is a popular governor, I think the policies of this administration and Democrats in Washington [are] not,” he said.

Cornyn also appeared to test a few lines of attack Republicans will use against Manchin in the special election.

“Gov. Manchin would have voted for the stimulus. He supported the health care bill. Those are unpopular policies in a state like West Virginia that has about a 35 percent approval rating for the president.”

During the interview, Cornyn also gave some insight into his committee’s June fundraising totals, which are set to be released Tuesday.

Cornyn said the NRSC raised “north of $4 million” in June. His committee raised $3.6 million in May and, more importantly, showed more cash on hand than the Democratic Senatorial Campaign Committee for the first time since early 2009. The NRSC had $18.1 million in the bank compared with about $17.6 million for the DSCC on May 31. The DSCC has yet to release its June fundraising totals.

Some insiders have speculated that the NRSC has benefited recently from GOP donors taking a pass on giving to the Republican National Committee because of a string of high-profile gaffes made by Chairman Michael Steele that have led to questions about his stewardship of that committee.

Cornyn said donors are giving to the NRSC this cycle because they realize the Senate is where the action is in 2010.

“It’s no secret the RNC has had some problems this time and frankly we have reached out to major donors and said, ‘You know what, for this cycle we would encourage you to give to the Senate committee because of the structure of the Senate. Because of the importance of 41 votes.’ … It seems to be a message people are accepting and responding to,” Cornyn said.