"If elected, he would enter Congress as a senior member"
Then call Hedgecock's show and dispute Bilbray yourself. He accomplished a lot in his 3 terms and his seniority is in tact.
"I doubt that Hastert will offer anything to Bilbray".
I happen to doubt you are correct. Hastert gave Lungren his seniority back, just one year ago. Lungren was also in an even more heavily republican district than Bilbray is running in. It is a tradition that the speaker grants seniority to returning members and there is frankly abosolutely no reason to believe the Speaker would grant it to Lungren and not Bilbray. It is pretty much a given he will get it back.