(CNN)- The 2016 presidential field will grow this week with more Republicans. Well-known politicians from Pennsylvania and New York, Rick Santorum and George Pataki, are expected to enter the race. More candidates will mean a longer competition for resources, money and time to make an impact. 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 the second-place finisher from the previous cycle. “Republican parties are conservative. We stick with tradition. I would encourage you to do that in this election.,” said Santorum. 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 look 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,” said Pataki. 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 GOP tally to 10. That number doesn’t include potential front-runners Jeb Bush and Scott Walker, plus Chris Christie, John Kasich, Bobby Jindal and possibly others. The Democrats may also get a new 2016 contender. Former Maryland Governor Martin O’Malley is set to announce if he will run Saturday.