Editor's note: Ed Rollins, a senior political contributor for CNN, is senior presidential fellow at the Kalikow Center for the Study of the American Presidency at Hofstra University. He is a principal with the Dilenschneider Group, a global public relations firm. He was White House political director for President Ronald Reagan and chairman of the National Republican Congressional Committee.
New York (CNN) -- Since the early '80s, nearly every major boxing championship or featured bout has had a golden-voiced announcer, Michael Buffer, who began the bout with the pronouncement "Let's get ready to rumble!"
Even though Buffer has the term trademarked, House Speaker Nancy Pelosi articulated a message similar to his when she sent her troops off to battle this week.
And a rumble we will have! With less than four weeks until election day, our television sets, radios, mailboxes, telephones and computer screens will be filled with pounding messages, some truthful and some stretching the truth.
The purpose of course is to get you to vote for someone -- or against someone. Unfortunately it is easier to make the voters believe the negatives and react accordingly. The Democrats have decided that the only way they can hold onto their majorities is to make the Republicans an unacceptable alternative.
"Now our challenge is to tattoo the practices of big insurance, big oil, big banks and the rest onto Republican opponents," Pelosi is quoted as saying to The New York Times, "and our members feel very good about doing that."
What they obviously don't feel very good about is explaining a record of increased deficit spending, the expansion of government programs, jumps in the numbers of federal employees or the nation's high unemployment rate -- all of which happened on their watch.
They also don't want to explain why they didn't pass a budget or even a budget resolution this year, which is their most important job. They also don't want to explain why they didn't vote on extending the tax cuts that they and the president have promised for two years.
The speaker and her key political lieutenants now know they can't sell their legislative agenda to voters who are either confused by the programs or don't approve of them. What voters know is that it's going to cost them more tax dollars. Remember this was the same Pelosi who said during the health care battle: "But we have to pass the bill so that you can find out what is in it, away from the fog of controversy."
Now she tells her endangered incumbents: "Members don't have to go out and defend the entire-every chapter and verse of the health care bill." The controversy and confusion was partly enabled by Pelosi so we wouldn't know what is in the most far reaching and one of the most expensive pieces of legislation ever passed by a Congress.
Since the Democrats can't sell a positive message, they have to resort to the oldest rule in politics: When you're behind, attack and change the subject.
Even though the anti-incumbent, anti-Washington movement has been growing, campaigns are not won by the polls but by voters, and the voters are still to be heard from. Republicans see nothing but positive signs. Yet the battle is just being waged and many of the races are very close.
This is the lay of the land as the professional handicappers see it:
The House is the most obvious battleground. Republicans must win 39 seats to become the majority and allow Pelosi to be the full-time representative of the city of San Francisco. The campaign committees that oversee the races are watching closely between 80 and 90 seats that are either competitive or could become competitive in the closing weeks.
Seven of those are Republican seats and the rest are Democratic. Most of the strongest challenges are against Democratic incumbents who beat Republican incumbents in 2006 (31) or in 2008 (21). More than 40 of those Democratic seats are rated as toss-ups today. Three or four Republicans are in the same category.
So in spite of the enthusiasm on the Republican side and the greater voter intensity, a lot has to happen for Republicans to win the majority. It can happen and I believe it will -- but it's about whose voters turn out to vote and how the campaigns execute in the closing weeks.
In the Senate, it is more difficult for Republicans to win the majority. They must win 10 seats; tough but not impossible. There are 37 seats up this year and 18 of those seats are safe seats. Most predictions are for Republicans to make a gain of 6 to 7 seats.
If you stay up late on election night and wait for the West Coast results and see that Sen. Harry Reid of Nevada, Sen. Patty Murray of Washington and Sen. Barbara Boxer of California are losing or have lost, know that a political earthquake has shaken the landscape and Republicans are in control of both Houses of Congress.
But I warn Republican candidates everywhere, in this environment it's yours to win but you can lose. Just remember the challenge Madam Speaker issued to her vulnerable incumbents who were publicly criticizing her to gain support in their districts. "[Just] go for it; just win your election!" That's a woman who will do anything to win! Republicans you have been forewarned. The rumble is on! And the rumble's not over until the fight is finished.
The opinions expressed in this commentary are solely those of Ed Rollins.