Republican U.S. Senate challenger Joel Dykstra says he'll hold town hall meetings with voters in the absence of campaign debates with Democratic Sen. Tim Johnson.

He invited his election opponent to take part and said Johnson's decision not to debate because of speech limitations is a smoke screen.

"I think the decision to stay out of the debate is more about the risk of, frankly, having to answer some questions and certainly the risk of participating in an unscripted, less controlled exchange with the voters and with the media," Dykstra told reporters Tuesday.

In response, Johnson said he will have plenty of dialogue with voters through his schedule of public meetings and forums, including FarmFest near Mitchell and the State Fair. He said he will spend August in South Dakota and does not plan to attend the Democratic National Convention in Denver.

"I will defend my position more fully than I could in the debate," he said. "I will encourage back and forth and the response I make will be good or bad."

Johnson's speech is slow and slurred and some words are hard to understand, a side effect of a December 2006 brain hemorrhage that left him weak on his right side.

"While my speech continues to improve it is not yet 100 percent, obviously, and I've not reached a point in my speech where my participation in the debate would accurately reflect my capabilities," he said.

Dykstra said his campaign had accepted five debate invitations and expected more to come when Johnson announced last week that he would not participate in campaign debates.

The Republican state lawmaker from Canton acknowledged that debates would offer him important exposure as the challenger to a two-term incumbent.

Dykstra said town hall meetings already are set for Sioux Falls, Rapid City, Aberdeen and Pierre starting in late September. Eight or 10 might be held in all.

"We are clearly responding to the fact that we won't have that (debate) access, that the voters and the media won't have the opportunity to speak directly with Senator Johnson in a public forum to weigh the positions of the two candidates side by side," Dykstra said.

He said each meeting would have a central theme that he would address; then he will take questions on that issue or any other.

"I would invite Senator Johnson to participate in any or all of these events. We will have an open opportunity for that. We'd be open to adjustments to the format or anything that would make it more comfortable for him to participate."

Johnson talked to reporters in Sioux Falls after a 30-minute discussion about gas prices with five people representing education, business and social service agencies. Johnson's office said he will visit 19 South Dakota communities before Congress reconvenes in September.