Rick Santorum abruptly cancelled his bid for the U.S. presidency today, without giving a specific reason, CNN is reporting. 

The decision effectively hands the Republican nomination to Mitt Romney.

Santorum had suspended campaigning over the weekend after his daughter Isabella, 3, was hospitalized. She suffers from Trisomy 18, a serious chromosomal condition that interferes with development.

The upcoming April 24 primary was looking dubious for Santorum, with tightening poll numbers, which may have influencd his decision. He represented one of the primary states, Pennsylvania, as a U.S. senator.

What do you think of Santorum's decision? How do you feel about Romney being the likely nominee? And what is Gingrich still doing in the race?