By Matt Haber

May 19, 2008 | 4:02 p.m

Chris Matthews cannot be stopped. A month after singing his 'aria' in The New York Times Magazine and almost announcing his intention to run for office on The Colbert Report, the host of MSNBC's Hardball is now conquering Hollywood.

Matthews appears as himself in the trailer for Swing Vote, a film that appears to be a gentle political comedy starring a leathery Kevin Costner as a man whose vote—his solitary vote—will decide the presidential election.

Costner stars alongside Kelsey Grammer and Dennis Hopper as presidential candidates, Nathan Lane and Stanley Tucci as (at least according to the trailer) political operatives, and Madeline Carroll as Mr. Costner's adorable, smart-aleck daughter. Did we mention Judge Reinhold? He's in it, too. (Please, please—fingers crossed—let Mr. Reinhold play a Supreme Court justice so that Entertainment Weekly can take its "Here Comes The Judge" headline out of mothballs.) Willie Nelson's also in it for some added folksiness.

But the most important cameo appears to be Mr. Matthews'. He shows up at about the 50-second mark in the trailer to shout this bit of helpful exposition:

 

Mr. Matthews has previously flexed his acting muscles in Ivan Reitman's 1993 political comedy Dave. On the small screen, he's appeared in Robert Altman and Garry Trudeau's HBO series Tanner '88, Aaron Sorkin's White House drama The West Wing, Lawrence O'Donnell's very short-lived series, Mister Sterling, and in Tina Fey's sitcom 30 Rock. In each project, he played himself.