It's too soon to know whether the boost the tea party- backed Senate candidates are anticipating will materialize, said Jennifer Duffy, who tracks Senate races for the Cook Report.
With the exception of Louisville investor Matt Bevin, who is spending his own money in his primary race against McConnell, "none of these other candidates are really serious yet," Duffy said.
"It's going to take a week or so to figure out how tea party voters feel about it," Duffy said. "If they are angry, that could give some of these candidates momentum."
Democrats are also looking to use the government shutdown battle to their political advantage.
Rickey Cole, the Democratic chairman in Mississippi, said a Republican civil war presents an opportunity. Cole is pitching party leaders in Washington to help in recruiting a candidate for the state's Senate contest.
"Folks are returning my call, but everybody's got to do a poll to decide which side of the bed to get out of," Cole said in an interview. "This race could be a replay of what happened to Senator Lugar in Indiana."
After 36 years in the Senate, Dick Lugar lost the Republican primary in Indiana last year to state Treasurer Richard Mourdock, who had tea party support. Mourdock went on to lose to Democrat Joe Donnelly in the general election.
The Democratic Senatorial Campaign Committee, which assists candidates, is attacking the Republican House members who are running for the Senate, saying they're partly to blame for the unpopular shutdown.
Montana, West Virginia and Georgia Senate contests all feature Republican House members running for seats where incumbents are retiring. In Arkansas and Louisiana, Democratic senators are squaring off against House Republicans.
"Republicans are immeasurably damaged by this," said the Democratic committee's spokesman, Justin Barasky. "They repeatedly voted to keep the government shutdown. It highlights a recklessness and irresponsibility that all those candidates have."