RENO, Nev. (AP) – Bernie Sanders is pronouncing himself startled by the ferocity of Hillary Clinton’s attempts to take him down.

He says she’s coming “unraveled” by his progress in the Democratic presidential campaign.

The Vermont senator used unusually blunt words to express frustration with his opponent when he spoke to reporters in Nevada on Saturday before flying to Colorado for a Democratic dinner at which both are scheduled to appear.

Clinton has sharpened her argument in recent days that Sanders is pitching unrealistic ideas and lacks foreign policy depth.

Also in Nevada on Saturday, Clinton said Sanders’ health plan would cost Americans an “enormous” amount of taxes.

Sanders says Clinton is coming “unraveled” by his strong second-place showing in Iowa’s caucuses and rout in New Hampshire’s primary.