Welcome to Trail Guide, your daily tour along the road to the White House. I'ts been a busy weekend on the campaign trail. Here's what we're watching this morning:
- Donald Trump appears to have crossed the line with his comments on John McCain
- Martin O'Malley and Bernie Sanders crossed the Netroots nation
- Ted Cruz and Bobby Jindal were crowd favorites at a confab of Christian conservatives in Iowa
- Marco Rubio and Scott Walker hit the Sunday shows