There don't seem to be any results available anywhere for the 1920 elections, so with that in mind, here are the three other Austrian interwar elections.
In 1923, a fairly dull election campaign saw the incumbent
Bürgerblock government under Ignaz Seipel retain power - the German-National bloc lost a lot of votes, but because the CS fell one seat short of an absolute majority, the coalition was the only stable option.
The remaining four years were, um, about as quiet as it's possible for interwar Central Europe to get, and in 1927, the governing parties decided to stand for re-election as a unified list (
Einheitsliste) - this was probably a tactical error, as the unified list barely improved on the CS result in 1923. The
Landbund made big strides as a result, but did not succeed in depriving the unified list of a majority in the chamber. The SDAP made slight improvements on their 1923 result, and it looked for all the world like polarisation was setting in.
The
Bürgerblock government fell in autumn 1930, when the CS nominated a Chancellor who was unpalatable to the German National side, and the succeeding CS minority government called fresh elections. By this point, the stable equilibrium was being undermined by the growth of paramilitary radicalism. The
Heimwehr, a loose organisation of ex-military men who originally formed to combat Slovene interests in southeastern Carinthia during the referendum there in 1920, had been on the rise ever since, and the first big clashes between them and the SDAP-supported
Republikanischer Schutzbund ensued in 1927 after a group of
Heimwehr men were acquitted of murdering a child during a demonstration. In May 1930,
Heimwehr groups from around the country had gathered in Korneuburg, north of Vienna, and sworn what became known as the Korneuburg Oath, proclaiming support for "renewing Austria from the ground up" and opposition to both Marxism and German nationalism. From this point on, the formerly loose-knit
Heimwehr became one of Austria's strongest political movements. When the government fell and the National Council was dissolved, they very hastily threw together an electoral organisation dubbed the
Heimatblock ("Homeland Bloc"), and put up the eccentric nobleman and former Nazi Ernst Rüdiger Starhemberg as their candidate for Chancellor.
The
Heimatblock would only get around six percent of the vote, becoming the smallest party in the new chamber, but their entrance emboldened sympathetic elements within the CS and discredited the more pro-democratic elements in the government. In 1931, the
Creditanstalt, Austria's oldest and largest bank, declared bankruptcy, and the bailout proposed by Chancellor Ender brought down the government once more. A brief CS minority was followed by the installation of Engelbert Dollfuß, former Agriculture Minister and known corporatist, at the head of a CS-GDVP-HB coalition. In March 1933, a heated debate in the National Council resulted in all three speakers resigning - Dollfuß, never a man to look a gift horse in the mouth, declared the chamber "self-eliminated", and sent in the police to occupy the parliament building and prevent them from assembling again. Soon after, the governing parties were merged into the
Vaterländische Front (Patriotic Front - usually rendered as "Fatherland Front" in English) and all others - most prominently the SDAP - were banned. The forcible disarmament of the
Schutzbund resulted in four days of armed struggle during February 1934, which is generally known in German as the
Februarkämpfe (February Struggles) and in English as the Austrian Civil War, and ended with the total defeat of the
Schutzbund.
Now in complete control of the country, Dollfuß proclaimed a new constitution abolishing liberal democracy, and ruled as the fascist dictator of Austria for two months before getting shot. His assassins were not left-wingers, but rather Austrian Nazis (we
hate Austrian Nazis) who thought this would be a great time to insert themselves into all of this. The assassination was followed by a general coup attempt, which was foiled by Dollfuß' successor as Chancellor, Kurt Schuschnigg, who would go on to rule the "Austrofascist" state for four years before the Nazis totally overpowered him and forced Austria's annexation into Germany in March 1938.