I've no idea why you keep thinking something in what I said translated as "Secret Service ignores threats to congressmen". They are law enforcement, they certainly can and presumably do alert the proper authorities to any major possible crime they expect, they do not protect congressmen, same as they don't protect SCOTUS, governors, or anyone else unless they qualify for one of the following.

Today, the Secret Service is authorized by law to protect:
The President, the Vice President, the President-elect and Vice President-elect
The immediate families of the above individuals
Former Presidents and their spouses for their lifetimes except when the spouse remarries. In 1997, legislation became effective limiting Secret Service protection to former Presidents for a period of not more than 10 years from the date the former President leaves office
Children of former Presidents until age 16 or 5 years after the presidency
Former Vice Presidents until 6 months after their term ends: (the Secretary of Homeland Security can extend the protection time.)
Families of former Vice Presidents until 6 months after term ends
Visiting heads of states or governments and their spouses traveling with them, other distinguished foreign visitors to the United States, and official representatives of the United States performing special missions abroad whom the president deems important enough for protection outside the Diplomatic Security Service
Major presidential and vice presidential candidates, and their spouses within 120 days of a general presidential election
Other individuals as designated per executive order of the President
National Special Security Events, when designated as such by the Secretary of Homeland Security