Czechoslovakia's centralized political structure might have been well suited to a single nation-state, but it proved inadequate for a multinational state. Constitutional protection of minority languages and culture notwithstanding, the major nonCzech nationalities demanded broader political autonomy. Political autonomy was a particularly grave issue for the Czechs' partners, the Slovaks. In 1918 Masaryk signed an agreement with American Slovaks in Pittsburgh, promising Slovak autonomy. The provisional National Assembly, however, agreed on the temporary need for centralized government to secure the stability of the new state. The Hlasists, centered on the journal Hlas, continued to favor the drawing together of Czechs and Slovaks. Although the Hlasists did not form a separate political party, they dominated Slovak politics in the early stages of the republic. The Hlasists' support of Prague's centralization policy was bitterly challenged by the Slovak Populist Party. The party had been founded by a Catholic priest, Andrej Hlinka, in December 1918. Hlinka argued for Slovak autonomy both in the National Assembly and at the Paris Peace Conference. He made Slovak autonomy the cornerstone of his policy until his death in August 1938.

The Slovak Populist Party was Catholic in orientation and found its support among Slovak Catholics, many of whom objected to the secularist tendencies of the Czechs. Religious differences compounded secular problems. The Slovak peasantry had suffered hardships during the period of economic readjustment after the disintegration of the Hapsburg Empire. Moreover, the apparent lack of qualified Slovaks had led to the importation of Czechs into Slovakia to fill jobs (formerly held by Hungarians) in administration, education, and the judiciary. Nevertheless, at the height of its popularity in 1925, the Slovak Populist Party polled only 32 percent of the Slovak vote, although Catholics constituted approximately 80 percent of the population. Then, in 1927, a modest concession by Prague granted Slovakia the status of a separate province, and Slovak Populists joined the central government. Monsignor Jozef Tiso and Marko Gazlik from Slovakia were appointed to the cabinet.

Although Hlinka's objective was Slovak autonomy within a democratic Czechoslovak state, his party contained a more radical wing, led by Vojtech Tuka. From the early 1920s, Tuka maintained secret contacts with Austria, Hungary, and Hitler's National Socialists (Nazis). He set up the Rodobrana (semimilitary units) and published subversive literature. Tuka gained the support of the younger members of the Slovak Populist Party, who called themselves Nastupists, after the journal Nastup.

Tuka's arrest and trial in 1929 precipitated the reorientation of Hlinka's party in a totalitarian direction. The Nastupists gained control of the party; Slovak Populists resigned from the government. In subsequent years the party's popularity dropped slightly. In 1935 it polled 30 percent of the vote and again refused to join the government. In 1936 Slovak Populists demanded a Czechoslovak alliance with Hitler's Germany and Mussolini's Italy. In September 1938, the Slovak Populist Party received instructions from Hitler to press its demands for Slovak autonomy.

Data as of August 1987