Could US Senators or US Representatives be recalled?

Excerpts from Jack Maskell's Recall of Legislators and the Removal of Members of Congress from Office are italicized:

As to removal by recall, the United States Constitution does not provide for nor authorize the recall of United States officers such as Senators, Representatives, or the President or Vice President, and thus no Member of Congress has ever been recalled in the history of the United States...Although the Supreme Court has not needed to directly address the subject of recall of Members of Congress, other Supreme Court decisions, as well as the weight of other judicial and administrative decisions, rulings and opinions, indicate that: (1) the right to remove a Member of Congress before the expiration of his or her constitutionally established term of office is one which resides exclusively in each House of Congress as established in the expulsion clause of the United States Constitution, and (2) the length and number of the terms of office for federal officials, established and agreed upon by the States in the Constitution creating that Federal Government, may not be unilaterally changed by an individual State, such as through the enactment of a recall provision or a term limitation for a United States Senator or Representative. Under Supreme Court constitutional interpretation, since individual States never had the original sovereign authority to unilaterally change the terms and conditions of service of federal officials agreed to and established in the Constitution, such a power could not be “reserved� under the 10th Amendment...

In some States, State legislators and other State or local elected officials may be removed from office before the expiration of their established terms not only by action of the legislature itself through an expulsion (or for executive officers, through an “impeachment� and conviction by the legislature), but also by the voters through a “recall� election procedure. While an expulsion is an inherent authority of legislative bodies incident to their general powers over their own proceedings and members, recall is a special process outside of the legislature itself, exercised by the people through a special election...

The United States Constitution does not provide for nor authorize the recall of United States officials such as United States Senators, Representatives to Congress, or the President or Vice President of the United States, and thus no United States Senator or Member of the House of Representatives has ever been recalled in the history of the United States.

http://lugar.senate.gov/CRS%20reports/R ... Office.pdf