Several Republican groups are stepping up the pressure on Democrats to disavow Sen. Robert Menendez (D-NJ), whose public corruption trial begins in a New Jersey federal courtroom today.

In a statement released this morning one of those groups, America Rising PAC, noted that “only 12 sitting Senators have been indicted” in the history of the United States Senate.

“Senator Menendez has the most on the line during his corruption trial, but the stakes are also high for the Democratic Party,” the statement continues.

Menendez is on trial along with Dr. Salomon Melgen, his long time political contributor and ally. Menendez is charged with attempting to use his political influence to get the Department of Health and Human Services to reverse a regulatory determination that Melgen owed the federal government $8 million for fraudulent billing practices, the same practices for which he was convicted of on 67 felony counts of Medicare fraud totaling over $105 million in April.

In return, the government alleges, Menendez received the benefits of over $700,000 in political contributions made to PACs that supported his 2012 re-election campaign, as well as travel for at least a dozen trips to the Dominican Republic and Florida paid for by Melgen. Menendez belatedly reimbursed Melgen $58,000 for three of those trips, but the other trips remain unreimbursed.

America Rising PAC points out that the Menendez trial hurts the Democratic Party in three ways.

First, due to a ruling by U.S. District Judge William Walls, who is presiding over the trial, Menendez will be unable to vote in the United States Senate during the trial, which will not be delayed to accomodate the schedule of Senate votes. This means that on upcoming key votes, the Democrats, already down 52 to 48, will have one fewer vote available.

“That means that Senator Menendez will be an empty desk for Senate Democrats this fall. Furthermore, New Jersey will be shortchanged one Senator during critical moments, which is not something that will play will with votes,” the America Rising Statement notes.

Second, in the event that Menendez is convicted — a potential outcome that was bolstered by last week’s Department of Justice brief that Menendez has concealed up to a dozen trips paid for by Melgen which he failed to report and the possibility that Melgen could provide evidence against him in return for a lighter sentence — Senate Democrats will be forced to make a difficult choice: Vote to expel Menendez from the Senate and lose a Democrat vote, or be subjected to wilting public criticism over hypocricy.

“In 2008, then-Senator Ted Stevens (a Republican) was convicted of multiple felonies. Following his felony conviction, Barack Obama called on Stevens to ‘step down’ from the Senate. Harry Reid added that ‘a convicted felon is not going to be able to serve in the United States Senate.’ . . . If Senator Menendez is convicted . . . Every single Senate Democrat will need to state publicly where they stand: with the desperate partisanship of Chuck Schumer or with the rule of law,” the America Rising statement said.

Finally, Menendez’s “deep ties throughout the Democratic Party” could hurt other Democrats currently or once in the U.S. Senate, America Rising contends.

“Just this year, Senator Menendez has made the following contributions: $5,000 to Senator Chris Murphy (D-CT), $10,000 to Senator Jon Tester (D-MT), $10,000 to Senator Debbie Stabenow (D-MI), $10,000 to Senator Kirsten Gillibrand (D-NY), $5,000 to Senator Elizabeth Warren (D-MA), and $10,000 to Senator Tim Kaine (D-VA),” America Rising notes.

In addition, “federal prosecutors have alleged in their briefs filed last week the ways in which former Senate Majority Leader Harry Reid was complicit in Senator Menendez’s web of illicit actiivty,” America Rising concludes.

The America Rising PAC is not the only Republican group pointing out the political difficulties the Menendez trial poses for the Democratic Party.

The Republican National Committee has also sent out numerous communications in recent days elaborating upon those difficulties.