Iowa GOP insider Doug Gross, a Des Moines attorney who once worked as Governor Terry Branstad’s chief of staff, says the candidate he’s backing in the GOP’s U.S. Senate race is attractive, in part, because he has the financial resources to bankroll his own campaign. Mark Jacobs is a wealthy business executive who recently retired and moved back to Iowa.

“Not only does he have the ability to raise money, he also has his own money that he’s willing to commit to the race,” Gross says, “so Mark has an advantage there.”

Jacobs formally kicked off his campaign earlier this month and declined to tell reporters how much of his fortune he would spend on the race. Gross argues the Senate race “hasn’t started in earnest yet” and the candidates will have to prove they can raise money to be competitive.

“The awareness of folks in that race right now is well below 50 percent, even among likely Republican primary voters,” Gross says, “so people don’t know enough about them to make decisions, so they’ve got to have enough money to get their name out.”

Gross predicts January through April will serve as a weeding out period.

“Some of those candidates, I suspect, will have to drop out because they’re not raising money during that time frame and won’t be able to be competitive,” Gross says. “So if  you have three or four candidates, I think it’s more than possible one of those candidates will get more than 35 percent.”

In Iowa, a candidate must secure at least 35 percent of the vote in a primary to secure his or her party’s nomination. Gross barely crossed that 35 percent threshold himself in 2002 when he won the GOP’s nomination for governor. One of his competitors back then was Bob Vander Plaats, the Christian conservative who ran for governor again in 2006 and 2010 and is considering a run for the U.S. Senate in 2014.

“This poll came out recently about the Republican primary candidates and they included Bob Vander Plaats in that and took a look at it and I think he got 28 percent of the vote,” Gross says. “…Bob’s name identification at this point is probably at 90 percent among likely Republican primary voters and the fact that Bob is only at 28 and you need at least 35 percent to avoid a convention indicates to me that not even Bob would be a lock-cinch if he were to decide to run.”

Gross made his comments today during taping of the Iowa Public Television program, “Iowa Press,” which will air Friday night at 7:30.