Donald Trump is now in the lead among Iowa Republicans, according to the latest CBS/You Gov poll released Sunday morning.

Trump had fallen behind Ben Carson, but with Carson losing favor among Republican caucus-goers, Trump has retaken the lead while Texas Senator Ted Cruz has gained significant momentum to take the second place spot.

CBS reports that Cruz is picking up support from former Carson voters:

Since last month, Ted Cruz has gained ground -- and Ben Carson has lost ground -- among some key voting groups in Iowa: evangelicals, Tea Party supporters, those who are very conservative and older voters. And while Trump still leads among some of these groups, it's Cruz who is ahead among the very conservative, and Trump leads Cruz by just two points among evangelical voters.

Cruz's move has come directly at the expense of Carson, as nearly one-quarter of his voters switched.  

Among Iowa Republicans Trump has 30% support, Cruz 21%, Carson 19% and Rubio 11%. All other candidates are in single digits.

Meanwhile in New Hampshire, Marco Rubio is taking the second place spot. In the Granite state Trump has 32% support among Republicans, Rubio 13%, Cruz and Carson each have 10% support. 

Trump has held a strong lead in New Hampshire for several months but had lost ground in Iowa putting him tied or trailing Carson, depending on the poll.