The law was only Coolidge's first profession. His second career was politics, which satisfied his craving for civic service and supplemented his income. He found his entry into politics easy because his father had been a frequent officeholder in Vermont and because his legal mentors, Hammond and Field, were political leaders in Northampton. In 1896, Coolidge became active in the local Republican party, and in 1898 he was elected to the Northampton city council. From then on, his progress up the political ladder was almost constant. He became city solicitor in 1900, clerk of the Hampshire county courts in 1903, and chairman of Northampton's Republican committee in 1904. Coolidge suffered his only defeat at the polls when he ran for school committeeman in 1905.
That was the year Coolidge married Grace Anna Goodhue, a teacher in Northampton's Clarke Institute for the Deaf. The quiet Coolidge hoped that this charming young woman "having taught the deaf to hear, . . . might perhaps cause the mute to speak." Grace Coolidge was a vivacious, good-humored woman of varied interests who was willing to follow her husband's lead in all things. As such, she was the perfect helpmeet for her affectionate but domestically autocratic mate. Their first son, John, was born in 1906, and another, Calvin, in 1908.
Coolidge resumed his advancement up the political ladder in 1906 with his election to the Massachusetts House of Representatives, where during his two terms he established a mildly progressive legislative record. His ability to appeal unostentatiously to varied ethnic, religious, and economic interests was confirmed in 1909 when he became mayor of Northampton. In 1911, Coolidge was elected to the Massachusetts Senate, where for the first time he attracted notice on the state scene by helping to arrange a fair settlement of the great textile strike in Lawrence. Reelected to the state senate in 1912 and 1913, he was chosen president of that body in 1914, becoming the most prominent Republican holding state office. Coolidge performed effectively as senate president in 1914 and 1915, advising his colleagues to "do the day's work" and "be brief." In 1915 he was elected lieutenant governor.
Coolidge gave insight into his political success in a letter to a friend in 1915: "I think I have a reputation of being conservative, which I am, because I do not make so loud a noise as some others. I think I have been in sympathy with practically all legislation intended to improve living conditions." This could be translated into Coolidge's creed throughout his political career: something for everyone so long as it did not cost too much. Add to this the fact that he was a man who got along with almost everybody, who was compassionate with ordinary people while identifying with the well-to-do, and who was effective as an officeholder and remarkably shrewd in his political timing, and one has a politician who, while few could be enthusiastic about him, was acceptable to the majority.
After three years in the lieutenant governorship, Coolidge, recognized as a loyal, astute, and effective wheelhorse of his party in Massachusetts, had acquired enough support to run successfully for governor in 1918. He proved an able governor, one adept at riding the tides of the stormy post-World War I period, in part by skillfully manipulating the platitudes that he believed in and that people wanted to hear. He labored to hold down the escalating cost of living, to increase supplies of items in short supply, to penalize profiteers, to encourage reasonable pay increases, and to settle labor disputes. He successfully advocated ratification of the Nineteenth Amendment (for woman suffrage) and restriction of the work-week of women and children, among other reform measures. Moreover, Coolidge was instrumental in the efficient reorganization of the state's government.
His national reputation did not derive from such accomplishments but from his identification with settling the highly publicized Boston police strike of 1919. The police of Boston had serious grievances, which the authorities largely ignored. Thus, in September 1919 the police walked off their jobs, and disorder came to the Massachusetts capital. Coolidge did not intervene in the situation until peace had been substantially restored. Then the governor took command of the various forces that had been brought into Boston to maintain order. He upheld the police commissioner in refusing to allow the strikers to return to their jobs. When Samuel Gompers, president of the American Federation of Labor, contested him, Coolidge wrote to him, "There is no right to strike against the public safety by anybody, anywhere, any time." For this, during a time when disorder seemed to threaten the nation, Coolidge received America's acclaim. Moreover, that fall he was overwhelmingly reelected governor.
In 1920, Coolidge became a candidate for the Republican presidential nomination, but the efforts on his behalf amounted to little more than a favorite-son movement. After a sharp contest among many candidates, the Republican convention finally nominated Senator Warren G. Harding of Ohio for president. The delegates, in a surprise move, chose the Massachusetts governor to run for vice president. The Harding-Coolidge ticket won a landslide victory that November over Democrats James M. Cox and Franklin D. Roosevelt. As vice president, Coolidge was un-impressive. He sat in on cabinet meetings, but he played no significant role in the Harding administration. He was an uninspiring presiding officer of the Senate, and his speeches were little noted. By 1923, Coolidge was little more than a cipher on the national political scene.