The House and Senate Democratic campaign committees outraised their GOP counterparts 2-to-1 in June, according to monthly fundraising reports filed Monday.

The Democratic totals were boosted by a joint House-Senate fundraising dinner, held last month and headlined by President Barack Obama, that reportedly raised $3 million for the party’s efforts to defend its majorities in the 2010 elections.

Both parties held major fundraising events last month, but the June totals released Monday did not appear to reflect a big haul from the Republicans’ joint fundraising dinner in June.

The Democratic Senatorial Campaign Committee raised $6.2 million last month compared with the National Republican Senatorial Committee’s $3.4 million haul. The Democrats’ total accounts for roughly half of the $12.8 million that the committee raised from April 1 through June 30.

Senate Democrats also benefited from a Chicago event in June headlined by White House Chief of Staff Rahm Emanuel. Sen. Chris Dodd (Conn.), viewed as the most vulnerable Democrat up for re-election, reported receiving $30,000 from the event, which benefited several Senators as well as the DSCC.

The DSCC spent close to $2.3 million in June and ended the month with more than $7.9 million in cash on hand and a debt of more than $3.7 million. The committee began the cycle with close to $11 million in debts.

The NRSC ended June with $4.3 million in cash on hand after spending $2.9 million. It has no debt left from the previous cycle.

On the House side, the Democratic Congressional Campaign Committee raised more than $7.1 million last month while the National Republican Congressional Committee raised more than $3.1 million.

House Democrats also ended June with more than double the GOP’s cash on hand, although the DCCC is still carrying more debt from the 2008 cycle at this point.

The DCCC had more than $9.7 million in cash on hand as of June 30 and was $6 million in debt. The NRCC had close to $4.2 million in the bank and showed $3.25 million in debt from last cycle.

The DCCC spent more than $2.4 million in June while the NRCC spent more than $1.4 million. Both parties paid down some of their remaining debt last month, with the DCCC paying off roughly $67,000 and the NRCC paying down about $75,000.

For the year, the DCCC has raised close to $31 million while the NRCC has raised $17.5 million.