Washington (CNN) -- If you think the battle for the Republican presidential nomination has been a wild ride so far, hang on -- it could get even more exciting.
Five presidential debates are scheduled to be held in September and October, including two hosted and produced by CNN. A debate at the Reagan Presidential Library in southern California on September 7 is followed by a CNN debate in Tampa on September 12, and then followed by another Florida debate on September 22. A New Hampshire debate on October 11 is followed a week later by another CNN debate in Las Vegas, Nevada, on October 18.
Those five debates could further shape a race for the White House that was just altered over the past weekend with former Minnesota Gov. Tim Pawlenty's exit from the race and Texas Gov. Rick Perry's entrance into the contest.
Conventional wisdom is that Perry joins former Massachusetts Gov. Mitt Romney, who's making his second bid for the GOP nomination, and Rep. Michele Bachmann of Minnesota, as the top tier in the Republican fight. Romney has committed to all five debates, Bachmann, taking it a step at a time, has signed up through the September showdowns, but her campaign has said she will attend any debate Romney will attend. Perry, new to the race, has not yet committed to attending any of the debates.
"We've been in the race less than 48 hours and have not committed to any debates at this time," Perry campaign national press secretary Mark Miner told CNN Monday. "We will consider all the opportunities and dates and make the decisions in due time."
The debates could give all three candidates moments to shine, as well as to stumble.
"Debates, straw polls, are a danger to the top-tier candidates. They have very little to gain from them and everything to lose. They turn into events where the top-tier candidates put their faces on the bull's-eye for the media and the bottom-tier candidates," said GOP strategist and CNN contributor Alex Castellanos.
"And they often force the top-tier candidates to appeal to the narrower, conservative base of the GOP than to the broader group of independents the GOP candidate will need to defeat Obama in the fall of 2012," added Castellanos, who was a top media adviser to the 2004 Bush/Cheney re-election campaign and to Romney's 2008 bid for the Republican presidential nomination. He said he is not taking sides in the current battle for the Republican nomination.
We've also seen that debates so far this cycle have had consequences. In the days leading up to the June 13 CNN/WMUR/New Hampshire Union Leader debate, Pawlenty was criticizing the health care law passed in Massachusetts when Romney was governor, comparing it to and calling it the inspiration for the national health care plan signed into law last year by President Barack Obama. Pawlenty termed it "Obamney-care." But Pawlenty failed to go after Romney on the issue at the debate, even when given the opportunity by CNN's John King, the moderator.
"The Pawlenty experience should make it clear that these debates DO matter. His campaign was essentially over when he wouldn't take King's bait on the 'Obamney-care' issue," said Rich Galen, a Republican strategist who advised Fred Thompson during his 2008 GOP presidential bid, and who is the author of Mullings.com, an online column.
"The fact that the debate took place on June 13 and there were no other joint appearances scheduled until August 11 -- two months later -- meant that Pawlenty's 'timid' response stuck with him until (the debate) last Thursday."
The frequency of five debates over a two-month period may help negate the sort of blow that wounded Pawlenty.
"The good news about having a string of five debates over the next two months is, a candidate can make up for a bad -- or weak -- performance in debate No.2 with a strong appearance in debates 3 and 4. It's a little like striking out in the third with a man in scoring position. You know you're going to have several more at-bats to make up for it," Galen added.
But there's a downside to having five debates over two months: They could be overkill. As Galen says, "Each of them takes at least two days out of the campaign, and it would not surprise me to find that not everyone is in every one."
Take, for instance, the Bachmann campaign, which now has to build on Saturday's victory in the straw poll in Iowa.
"The last seven weeks have been totally focused on the Iowa straw poll and the first two debates. We now will have to expand and build our campaign to win the Iowa caucus, build our fundraising capacity and expand our political operation into other early primary states," says Ed Rollins, the Bachmann campaign manager, who also directed Reagan's landslide re-election bid in 1984 and managed former Arkansas Gov. Mike Huckabee's 2008 presidential campaign.
Just the five debates alone are enough to make the next two months tumultuous on the campaign trail, but as those 1-800 television ads say, "But wait, there's more!"
Sen. Jim DeMint of South Carolina, who is extremely influential among tea party activists and other grassroots conservatives, is inviting the leading presidential candidates to a forum in the Palmetto State on Labor Day. South Carolina is the first Southern state to vote in the race for the White House.
Many of the candidates also will be in Florida the last weekend of September to attend major events such as CPAC Florida, Presidency 5, and a straw poll. The same weekend some of the White House hopefuls will also attend a cattle call at the Mackinac Island Leadership Conference in Michigan.
In October, the Values Voter Summit in the nation's capital, and the Western Republican Leadership Conference in Las Vegas (Nevada is scheduled to vote third in the caucus and primary calendar) will also attract the presidential candidates.
Come November, we could be looking at an altered race, thanks to the crowded calendar in September and October.
Follow Paul Steinhauser on Twitter: @PSteinhauserCNN.