This is the week we will begin to see the GOP field blossom toward its eventual full size with the addition of multiple candidates with little chance of getting the nomination but with the potential to fracture the campaign in significant ways.
Already, Dr. Ben Carson and former Hewlett-Packard CEO Carly Fiorina have announced they are running. And former Arkansas Gov. Mike Huckabee is expected to join the race later this week.
That will put the field of announced or likely candidates at a dozen with possibly more to come. That's even more than 2012, which saw a parade of GOP front-runners and a race to the right that badly damaged eventually nominee Mitt Romney.
The 2016 field could wind up doing the exact same thing to whoever survives the primary contest, though the GOP has at least succeeded thus far in limiting the number of debates.
Of the three new candidates this week, Huckabee is perhaps the most potent. The former Fox news host is a darling of the religious right with the potential to mount a strong challenge in Iowa, where the evangelical vote remains dominant.
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Huckabee may not have the establishment support to translate a strong Iowa showing into further early state wins but he could push other candidates, including Jeb Bush, Marco Rubio and Scott Walker, to the right in ways that could complicate a general election campaign.
Carson is a major wild card. An African-American retired neurosurgeon, Carson has never held elective office. But he generates strong appeal in the party's conservative base and hopes to electrify audiences as the plain speaking, nonpolitician in the race. His odds are very long but dynamics in such crowded fields are hard to predict.
Fiorina also has a very tough path to the nomination. She will attempt to run in the business-friendly, center-right lane already occupied by Bush, Walker and Rubio. Fiorina failed in her only other political campaign, losing to California Democratic Sen. Barbara Boxer in 2010.
Fiorina will also have to contend with criticism of her tenure as HP CEO and her advocacy of an unpopular merger with Compaq that hammered the company's stock price and helped lead to her eventual ouster. The Democratic National Committee wasted no time on Monday blasting out a release criticizing Fiorina's business career as one characterized by "mass layoffs, tumbling stock prices, and a failed merger."
None of the new candidates in the GOP field is likely to challenge a strong group of front-runners for the eventual nomination. But the sheer size of the field suggests a long and grueling campaign that may not produce a nominee until late in the process.
In fact, the first few contests could all produce different winners with a more conservative candidate (Huckabee, Ted Cruz et al) taking Iowa, an establishment candidate (Walker, Bush, Rubio et al) winning New Hampshire and multiple contestants fighting it out in South Carolina and beyond.
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It is always possible that a single candidate will emerge as dominant early in the process. But with such a crowded field and no clear "next-in-line" candidate, it will be difficult. There is a case to be made that this process will toughen and battle test the eventual nominee. But there is an even stronger one to be made that it will batter the eventual standard bearer and cost vast sums of money even as Hillary Clinton and the Democrats hoard cash and prepare for the general election.
Clinton is not guaranteed the nomination without a fight but it does not seem that she will get any serious challenge. Former Baltimore mayor and Maryland Gov. Martin O'Malley is expected to announce soon and will put some pressure on Clinton from the left on trade and taxes. But he does not have the stature or the record to mount a serious insurgency. If Clinton is not the nominee it will be because of scandal or some unforeseen crisis and not because someone beats her.
But O'Malley, Sen. Bernie Sanders, who announced last week, and whoever else gets in on the Democratic side could wind up providing just the kind of light tune-up Clinton wants while the eventual GOP nominee gets beat up in a 15 round heavy weight brawl.
—Ben White is Politico's chief economic correspondent and a CNBC contributor. He also authors the daily tip sheet Politico Morning Money [politico.com/morningmoney]. Follow him on Twitter @morningmoneyben.