Expected to clear their candidacies on the Republican side are former Pennsylvanian Senator and previous candidate Rick Santorum, former New York Governor George Pataki. And for the Democrats, a potential challenger to Hillary Clinton–the former Maryland Governor Martin O'Malley is said to announce his decision on Saturday. 

 

We're bringing in CNN Senior Political Correspondent Brianna Keilar. And, Brianna, you know, there are so many Republican entering this race, it's a big field, a whole lot of experience there, but is the party concerned it's too big?

 

They are, in some ways, uh, John, because even though a crowded field means that candidates get this time to sharpen their political skills, it's also a conundrum for debate organizers, how do they fit everyone on one stage, maybe they just can't, as we've learnt. And more important, the longer this competition for resources, money and then time to make an impact drags on, the Republican nominee may find that they are in a disadvantage in the general election.

 

A packed Republican primary field (is) about to get even more crowded. So far, six candidates have already declared, and four more are expected to follow suit over the next two weeks.

 

First up, former Pennsylvania Senator Rick Santorum, who has an announcement event set for Wednesday. The runner-up to Mitt Romney in 2012 is encouraging Republicans to continue their tradition of going with their second place finisher from the previous cycle.

 

"Republican parties are conservative, we stick with traditions. I would encourage you to do that in this election.

 

Former New York Governor George Pataki will make his presidential ambitions clear Thursday in the first-in-the-nation primary state of New Hampshire.

 

"When I looked at the country and the world today, I think our country is at greater risk of losing our freedom than at any time in my lifetime."

 

Pataki and Santorum are likely to be joined next week by South Carolina Senator Lindsey Graham and former Texas Governor Rick Perry, which would bring the official G.O.P tally to ten. And that doesn't include potential front-runners Jeb Bush and Scott Walker, plus Chris Christie, John Kasich, and Bobby Jindal and possibly others.

 

Everybody's got a right, who qualifies, uh, to run. And, and, you know, we'll just ride this one out, with 15, 16–a football team worth of candidates starting off.

 

And watching all of this play out is of course Hillary Clinton. She and her husband Bill took part in the new capital New York Memorial Day Parade today. This is their first public event together since she declared, she's onto a southern swing South Carolina, Florida this week. 

 

But you also have Vermont Bernie Sanders, who is a candidate. He's holding his kick-off rally tomorrow, and then John, former Maryland Governor Martin O'Malley announcing his presidential plan Saturday in Baltimore. So the Democratic field getting, um, maybe a little bit more crowded, but still it's pretty roomy.

 

I say bring them on, good for business. 

 

Yeah.

 

Brianna Keilar.