How did he got into this esteemed position of authority?
He was born in a landless noble family, so instead of gambling away his inheritance he had to learn law. He got into politics in his county, as a reformist, but occasionally he represented aristocrats in the Hungarian Diet's upper house in their absence. 
There were plenty of nobles around the county - from the population of 11 million, over 5% were nobles in 1839, so what made him stand out from the lot? His journalist work!
In those times, after the Napoleonic wars, absolutist restoration choked the societies. In the countries of the Habsburgs not just censorship existed, but there weren't any political journalism. Most of the publications were literature or scientific. They could have political undertones, but weren't any political discourse similar to later ages. Széchenyi - a great aristocratic reformer of that era - founded a periodical dedicated to public affairs but when they started to publish about the sessions of the legislature, the Diet, they met backlash and censorship, and the threat of shut down.
The Diet too - at least some of the members - wanted to create its own publication, but the majority voted against.