Freshman Rep. Tom Cotton (R-Ark.) is expected to announce his candidacy for Senate on Tuesday, and Sen. Mark Pryor (D-Ark.) is already up with an attack ad.

The 60-second ad hits Cotton for "blind ambition" — i.e. running for the Senate seven months after first being sworn in to the House — but then turns to his congressional record.

It attacks Cotton for voting against the farm bill and the Senate's version of the Violence Against Women Act, as well as supporting the House GOP budget, which would turn Medicare into a voucher program.

According to Politico's Maggie Haberman, the ad buy is for two days only, at a cost of $45,000.

Cotton, 36, will speak at a barbeque tonight at 6 p.m. Eastern time in Dardanelle, Ark.

Pryor is considered the most vulnerable Democratic incumbent seeking reelection.