In 1866, Blair was elected as a Republican to the state assembly, and to the state senate the following year.  In 1874, he won the first of two consecutive terms in the U.S. House of Representatives (1875-1879).  He did not seek reelection in 1878, but was selected by the state legislature in June 1879 to fill a vacancy in the U.S. Senate, and reelected in 1885.  Blair gained a reputation as one of the Senate's busiest members, who, according to Harper's Weekly "introduced more bills, and ... occupied with speeches, reports, and preambles more pages of the official record than any other Senator."  

Besides supporting mainstream Republican policies like high tariffs, the gold standard, and generous pensions for Union war veterans, Blair was an ardent reformer who backed causes such as temperance, the rights of labor, federal aid to education, and women's suffrage.  He repeatedly introduced a bill to ban the manufacture, sale, and distribution of alcoholic beverages (to take effect in 1900), and in 1888 published a lengthy book on the subject, The Temperance Movement; or, The Conflict between Man and Alcohol.  As chairman of the Senate Education and Labor Committee, he held hearings in the mid-1880s on the relationship between business and labor, even-handedly soliciting the views of both labor and business representatives.  As a result, he drafted legislation to establish a federal bureau of labor statistics.  It was Blair's support of labor that led him to sponsor legislation closing America's borders to immigrant Chinese workers.

Blair was most well known for his sponsorship of the Blair Education Bill.  Motivated by concern for the plight of the former slaves in the South, the senator proposed that $77 million in federal funds for public schools be distributed to the states, proportionate to their illiteracy rates (which were much higher in the South), over several years.  The bill passed the Republican-controlled Senate three times during the 1880s, but the Democratic House speakers never allowed the bill to come up for a vote in the lower chamber.  Opponents were able to chip away at the support by arguing that the South was progressing toward general literacy, and in 1890 the bill failed in the Senate.

With Blair's defeat for reelection in 1891, President Harrison first offered him a federal judgeship, which he declined, and then, in March, the ministership to China, which he accepted.  His senate colleagues swiftly ratified the appointment, which, according to Harper's Weekly, some Washington wags interpreted as his fellow senators being "glad to assist in getting Colonel Blair as far as possible from Capitol Hill."  After China's strenuous protest, Blair tendered his resignation as minister, which the president accepted on October 6, 1891.  Thereafter, he practiced law in Washington, D.C., until his death in 1920 at the age of 85.

The major piece of federal legislation against Chinese immigrants was the Chinese Exclusion Act of 1882.  The law banned the immigration of Chinese laborers to the United States for a period of ten years.  It broke with the American tradition of open immigration and was the first federal law aimed at restricting a specifically named ethnic group.  The Scott Act of 1888 permanently banned the immigration or return of Chinese laborers to the United States.  The bill passed the House unanimously and met only slight resistance in the Senate (for legislatively undermining diplomatic negotiations). Mass demonstrations in California celebrated the new law. About 20,000 Chinese who had left the U.S. temporarily for China were refused reentry (including about 600 who were already traveling to America when the legislation was enacted). The Supreme Court upheld the Scott Act. The Chinese government, however, refused to recognize its legitimacy.

The Geary Act of 1892 extended for another decade all of the laws related to Chinese immigration. It established an internal passport system for all Chinese residents in the United States, by requiring them to apply for and carry a certificate of residence. If found without their certificate, they would be subject to deportation or imprisonment for a year of hard labor. Furthermore, bail was denied to Chinese involved in habeas corpus proceedings, and Chinese witnesses were prohibited from appearing in court. Chinese Americans and the Chinese government denounced the law. The U.S. Supreme Court upheld the Geary Act in 1893.

For more information on Chinese-Americans, visit HarpWeek's Immigration Website.