WASHINGTON (AP) — Caught off guard, congressional Democrats are grappling with President Barack Obama’s unexpected call for immediate access to insurance for those with pre-existing medical conditions, as well as richer Medicare drug benefits than envisioned in early versions of health care legislation. Additionally, Obama’s pledge in last week’s prime-time speech to hold the cost of legislation to about $900 billion over a decade has spread concern among House Democrats, who have long contemplated a costlier measure.