A campaign for the Iowa caucuses that has cycled through several Republican presidential front-runners entered its final week Monday, as unpredictable as the day that conservatives began competing to emerge as Mitt Romney's chief rival.
Romney, former governor of Massachusetts, released a new television commercial for Iowa in which he cited a "moral imperative for America to stop spending more money than we take in. It's killing jobs."
Texas Gov. Rick Perry countered with an ad that said four of his rivals have served a combined 63 years in Congress, "leaving us with debt, earmarks and bailouts."
Former Pennsylvania Sen. Rick Santorum, who has invested more time in Iowa than any other GOP candidate, countered that "most Americans now believe that a little bit of experience going into a job like president is probably a good thing."
Santorum was the only presidential candidate in the state Monday.
That changes today, with bus tours planned by Perry, former House Speaker Newt Gingrich and Minnesota Rep. Michele Bachmann.
Texas Rep. Ron Paul arrives Wednesday. Polls suggest he is peaking as caucus day nears, a rise that has him tied with Romney or even ahead.
There were signs of strategic shifts Monday as candidates struggled to stand out in advance of next Tuesday's voting that inaugurates the round of primaries and caucuses that will pick a nominee to oppose President Obama in the general election.
Perry's new ad shows images of Gingrich, Paul, Santorum and Bachmann as it criticizes Congress and renews the Texas governor's call for halving lawmakers' pay and time spent in Washington. Despite the commercial's implication, Gingrich and Santorum were out of Congress when the multibillion-dollar financial bailouts of 2008 occurred. Paul and Bachmann voted against the legislation.
The ad suggests that Perry is more concerned with outpacing Gingrich, Paul, Bachmann and Santorum here than he is in defeating Romney.
While others have periodically risen to challenge him, Romney has kept his support from seriously eroding.
A victory in Iowa does not necessarily translate into the Republican presidential nomination. Yet history suggests that candidates who finish farthest behind next week will quickly drop out, underscoring the significance of the struggle to emerge as Romney's chief rival.