By Julie Bosman

Updated: 3:38 a.m. ET Oct 26, 2007

WASHINGTON – If media muscle is any measure of a candidate, Representative Ron Paul of Texas is getting ready to flex his.

In the last two weeks, Mr. Paul — a Republican presidential candidate — has spent nearly a half-million dollars on radio advertisements in four early primary states, the first major media investment of his campaign. On Tuesday night, he will take a seat opposite Jay Leno.

And on Monday, a campaign spokesman said, he will roll out his first major television advertising campaign, spending $1.1 million on five new commercials to be shown in the New Hampshire market for the next six weeks. (In contrast, Rudolph W. Giuliani, the former mayor of New York and a rival for the Republican nomination, has yet to commit to any spending for television advertisements.)