By John Cranford and Rachel Bloom, CQ Staff

Republicans in Congress began edging away from President Bush and his policies last year, but a close look at voting patterns on Capitol Hill so far in 2008 shows GOP lawmakers breaking into a run.

Senators and House members from both parties have opposed the president far more often than at any other time since he’s been in the White House, and the erosion in support is dramatic among Republicans.

Until last year, Bush had historically high support scores among Republicans: No GOP president had done as well among fellow party members since 1953, when Congressional Quarterly began tabulating these things. Not even Ronald Reagan could boast of Bush’s degree of support.

Declining Support: Click Here to View Chart

GOP House members voted Bush’s way between 80 percent and 89 percent of the time on roll calls where he took a clear position during his first six years. Among Republican senators, his average support score had been even higher, reaching 94 percent twice, in 2001 and 2003.

In both chambers, Bush’s support faded a bit in 2007, but this year it has fallen through the floor. The average House Republican supported him just 63 percent of the time in 2008, and the average GOP senator, 68 percent.

Perhaps more surprising is that the president’s average score among House Republicans this year matches the low point recorded by the elder President George Bush in 1990 — the year he reneged on his “no new taxes” pledge and angered many in his party. And the president’s Senate average this year is lower than his father garnered in any of his four years in office.

The falloff is particularly evident among those Republicans engaged in difficult re-election campaigns. As the adjoining table shows, every GOP senator in a competitive race has supported Bush substantially less often this year than they did during his presidency as a whole. The same is true for House Republicans in toss-up races and for many of those in less-dire electoral circumstances.

On the other side of the aisle, Bush can’t take much comfort, either. His average support score among Senate Democrats is 36 percent this year, the lowest he’s ever seen, though the elder Bush had a 32 percent average support score among Senate Democrats in 1992.

And it would be hard for the current resident to fare worse than he did last year among House Democrats, who backed him just 7 percent of the time. His 14 percent average from that hardened group so far this year — if it holds up — will be the second-lowest score of all time among both parties in either chamber.

Still, a few House Democrats have given Bush a bit more support this year, especially some members who were elected in the past two years and are in extremely tight races.

But even Democratic Sen. Mary L. Landrieu of Louisiana, deemed most vulnerable in November, has been less supportive.

This study relied upon 443 roll call votes in the House since Jan. 3, 2001 — almost 9 percent of 5,159 total cast. For 2008 alone, 68 roll calls were included. In the Senate, 564 votes over the past seven-plus years, almost 22 percent of the 2,591 cast, had a presidential position. In 2008, presidential positions have been attached to 48 roll calls to date.